IOS字符串按特定字符拆分成数组
<span style="background-color: rgb(255, 255, 255);">NSString * fruits = @"apple,pair,banana,orange";
NSArray * array= [fruits componentsSeparatedByString:@","];</span><span style="background-color: rgb(255, 255, 255);">
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</span><div class="line alt1" style="padding: 0px !important; margin: 0px !important; border: 0px !important; outline: 0px !important; float: none !important; vertical-align: baseline !important; position: static !important; left: auto !important; top: auto !important; right: auto !important; bottom: auto !important; height: auto !important; width: auto !important; line-height: 1.1em !important; font-family: Consolas, 'Bitstream Vera Sans Mono', 'Courier New', Courier, monospace !important; font-size: 10pt !important; min-height: inherit !important;"><table class=" " style="border: 0px !important; padding: 0px !important; margin: 0px !important; outline: 0px !important; float: none !important; vertical-align: baseline !important; position: static !important; left: auto !important; top: auto !important; right: auto !important; bottom: auto !important; height: auto !important; width: auto !important; line-height: 1.1em !important; font-size: 10pt !important; min-height: inherit !important; border-collapse: collapse !important;"><tbody style="padding: 0px !important; margin: 0px !important; border: 0px !important; outline: 0px !important; float: none !important; vertical-align: baseline !important; position: static !important; left: auto !important; top: auto !important; right: auto !important; bottom: auto !important; height: auto !important; width: auto !important; line-height: 1.1em !important; font-size: 10pt !important; min-height: inherit !important;"><tr style="padding: 0px !important; margin: 0px !important; border: 0px !important; outline: 0px !important; float: none !important; vertical-align: baseline !important; position: static !important; left: auto !important; top: auto !important; right: auto !important; bottom: auto !important; height: auto !important; width: auto !important; line-height: 1.1em !important; font-size: 10pt !important; min-height: inherit !important;"><td class="content" style="font-family: Consolas, 'Bitstream Vera Sans Mono', 'Courier New', Courier, monospace !important; font-size: 10pt !important; border-width: 0px 0px 0px 3px !important; border-left-style: solid !important; border-left-color: rgb(108, 226, 108) !important; padding: 0px 0px 0px 0.5em !important; margin: 0px !important; outline: 0px !important; float: none !important; vertical-align: top !important; position: static !important; left: auto !important; top: auto !important; right: auto !important; bottom: auto !important; height: auto !important; width: auto !important; line-height: 1.1em !important; min-height: inherit !important;"><span style="background-color: rgb(255, 255, 255);"><code class="plain" style="padding: 0px !important; margin: 0px !important; border: 0px !important; outline: 0px !important; float: none !important; vertical-align: baseline !important; position: static !important; left: auto !important; top: auto !important; right: auto !important; bottom: auto !important; height: auto !important; width: auto !important; line-height: 1.1em !important; font-family: Consolas, 'Bitstream Vera Sans Mono', 'Courier New', Courier, monospace !important; font-size: 10pt !important; min-height: inherit !important;">NSString* string; </code><code class="comments" style="padding: 0px !important; margin: 0px !important; border: 0px !important; outline: 0px !important; float: none !important; vertical-align: baseline !important; position: static !important; left: auto !important; top: auto !important; right: auto !important; bottom: auto !important; height: auto !important; width: auto !important; line-height: 1.1em !important; font-family: Consolas, 'Bitstream Vera Sans Mono', 'Courier New', Courier, monospace !important; font-size: 10pt !important; min-height: inherit !important; color: rgb(0, 130, 0) !important;">// 结果字符串</code></span></td></tr></tbody></table></div><div class="line alt2" style="padding: 0px !important; margin: 0px !important; border: 0px !important; outline: 0px !important; float: none !important; vertical-align: baseline !important; position: static !important; left: auto !important; top: auto !important; right: auto !important; bottom: auto !important; height: auto !important; width: auto !important; line-height: 1.1em !important; font-family: Consolas, 'Bitstream Vera Sans Mono', 'Courier New', Courier, monospace !important; font-size: 10pt !important; min-height: inherit !important;"><table class=" " style="border: 0px !important; padding: 0px !important; margin: 0px !important; outline: 0px !important; float: none !important; vertical-align: baseline !important; position: static !important; left: auto !important; top: auto !important; right: auto !important; bottom: auto !important; height: auto !important; width: auto !important; line-height: 1.1em !important; font-size: 10pt !important; min-height: inherit !important; border-collapse: collapse !important;"><tbody style="padding: 0px !important; margin: 0px !important; border: 0px !important; outline: 0px !important; float: none !important; vertical-align: baseline !important; position: static !important; left: auto !important; top: auto !important; right: auto !important; bottom: auto !important; height: auto !important; width: auto !important; line-height: 1.1em !important; font-size: 10pt !important; min-height: inherit !important;"><tr style="padding: 0px !important; margin: 0px !important; border: 0px !important; outline: 0px !important; float: none !important; vertical-align: baseline !important; position: static !important; left: auto !important; top: auto !important; right: auto !important; bottom: auto !important; height: auto !important; width: auto !important; line-height: 1.1em !important; font-size: 10pt !important; min-height: inherit !important;"><td class="number" style="font-family: Consolas, 'Bitstream Vera Sans Mono', 'Courier New', Courier, monospace !important; font-size: 10pt !important; border: 0px !important; padding: 0px !important; margin: 0px !important; outline: 0px !important; float: none !important; vertical-align: top !important; position: static !important; left: auto !important; top: auto !important; right: auto !important; bottom: auto !important; height: auto !important; width: 3em !important; line-height: 1.1em !important; min-height: inherit !important; color: rgb(175, 175, 175) !important;"><code style="padding: 0px 0.3em 0px 0px !important; margin: 0px !important; border: 0px !important; outline: 0px !important; text-align: right !important; float: none !important; vertical-align: baseline !important; position: static !important; left: auto !important; top: auto !important; right: auto !important; bottom: auto !important; height: auto !important; width: 2.7em !important; line-height: 1.1em !important; font-family: Consolas, 'Bitstream Vera Sans Mono', 'Courier New', Courier, monospace !important; font-size: 10pt !important; min-height: inherit !important; display: block !important;"><span style="background-color: rgb(255, 255, 255);">02</span></code></td><td class="content" style="font-family: Consolas, 'Bitstream Vera Sans Mono', 'Courier New', Courier, monospace !important; font-size: 10pt !important; border-width: 0px 0px 0px 3px !important; border-left-style: solid !important; border-left-color: rgb(108, 226, 108) !important; padding: 0px 0px 0px 0.5em !important; margin: 0px !important; outline: 0px !important; float: none !important; vertical-align: top !important; position: static !important; left: auto !important; top: auto !important; right: auto !important; bottom: auto !important; height: auto !important; width: auto !important; line-height: 1.1em !important; min-height: inherit !important;"><span style="background-color: rgb(255, 255, 255);"><code class="plain" style="padding: 0px !important; margin: 0px !important; border: 0px !important; outline: 0px !important; float: none !important; vertical-align: baseline !important; position: static !important; left: auto !important; top: auto !important; right: auto !important; bottom: auto !important; height: auto !important; width: auto !important; line-height: 1.1em !important; font-family: Consolas, 'Bitstream Vera Sans Mono', 'Courier New', Courier, monospace !important; font-size: 10pt !important; min-height: inherit !important;">NSString* string1, string2; </code><code class="comments" style="padding: 0px !important; margin: 0px !important; border: 0px !important; outline: 0px !important; float: none !important; vertical-align: baseline !important; position: static !important; left: auto !important; top: auto !important; right: auto !important; bottom: auto !important; height: auto !important; width: auto !important; line-height: 1.1em !important; font-family: Consolas, 'Bitstream Vera Sans Mono', 'Courier New', Courier, monospace !important; font-size: 10pt !important; min-height: inherit !important; color: rgb(0, 130, 0) !important;">//已存在的字符串，需要将string1和string2连接起来</code></span></td></tr></tbody></table></div><div class="line alt1" style="padding: 0px !important; margin: 0px !important; border: 0px !important; outline: 0px !important; float: none !important; vertical-align: baseline !important; position: static !important; left: auto !important; top: auto !important; right: auto !important; bottom: auto !important; height: auto !important; width: auto !important; line-height: 1.1em !important; font-family: Consolas, 'Bitstream Vera Sans Mono', 'Courier New', Courier, monospace !important; font-size: 10pt !important; min-height: inherit !important;"><table class=" " style="border: 0px !important; padding: 0px !important; margin: 0px !important; outline: 0px !important; float: none !important; vertical-align: baseline !important; position: static !important; left: auto !important; top: auto !important; right: auto !important; bottom: auto !important; height: auto !important; width: auto !important; line-height: 1.1em !important; font-size: 10pt !important; min-height: inherit !important; border-collapse: collapse !important;"><tbody style="padding: 0px !important; margin: 0px !important; border: 0px !important; outline: 0px !important; float: none !important; vertical-align: baseline !important; position: static !important; left: auto !important; top: auto !important; right: auto !important; bottom: auto !important; height: auto !important; width: auto !important; line-height: 1.1em !important; font-size: 10pt !important; min-height: inherit !important;"><tr style="padding: 0px !important; margin: 0px !important; border: 0px !important; outline: 0px !important; float: none !important; vertical-align: baseline !important; position: static !important; left: auto !important; top: auto !important; right: auto !important; bottom: auto !important; height: auto !important; width: auto !important; line-height: 1.1em !important; font-size: 10pt !important; min-height: inherit !important;"><td class="number" style="font-family: Consolas, 'Bitstream Vera Sans Mono', 'Courier New', Courier, monospace !important; font-size: 10pt !important; border: 0px !important; padding: 0px !important; margin: 0px !important; outline: 0px !important; float: none !important; vertical-align: top !important; position: static !important; left: auto !important; top: auto !important; right: auto !important; bottom: auto !important; height: auto !important; width: 3em !important; line-height: 1.1em !important; min-height: inherit !important; color: rgb(175, 175, 175) !important;"><code style="padding: 0px 0.3em 0px 0px !important; margin: 0px !important; border: 0px !important; outline: 0px !important; text-align: right !important; float: none !important; vertical-align: baseline !important; position: static !important; left: auto !important; top: auto !important; right: auto !important; bottom: auto !important; height: auto !important; width: 2.7em !important; line-height: 1.1em !important; font-family: Consolas, 'Bitstream Vera Sans Mono', 'Courier New', Courier, monospace !important; font-size: 10pt !important; min-height: inherit !important; display: block !important;"><span style="background-color: rgb(255, 255, 255);">03</span></code></td><td class="content" style="font-family: Consolas, 'Bitstream Vera Sans Mono', 'Courier New', Courier, monospace !important; font-size: 10pt !important; border-width: 0px 0px 0px 3px !important; border-left-style: solid !important; border-left-color: rgb(108, 226, 108) !important; padding: 0px 0px 0px 0.5em !important; margin: 0px !important; outline: 0px !important; float: none !important; vertical-align: top !important; position: static !important; left: auto !important; top: auto !important; right: auto !important; bottom: auto !important; height: auto !important; width: auto !important; line-height: 1.1em !important; min-height: inherit !important;"><span style="background-color: rgb(255, 255, 255);">
</span></td></tr></tbody></table></div><div class="line alt2" style="padding: 0px !important; margin: 0px !important; border: 0px !important; outline: 0px !important; float: none !important; vertical-align: baseline !important; position: static !important; left: auto !important; top: auto !important; right: auto !important; bottom: auto !important; height: auto !important; width: auto !important; line-height: 1.1em !important; font-family: Consolas, 'Bitstream Vera Sans Mono', 'Courier New', Courier, monospace !important; font-size: 10pt !important; min-height: inherit !important;"><table class=" " style="border: 0px !important; padding: 0px !important; margin: 0px !important; outline: 0px !important; float: none !important; vertical-align: baseline !important; position: static !important; left: auto !important; top: auto !important; right: auto !important; bottom: auto !important; height: auto !important; width: auto !important; line-height: 1.1em !important; font-size: 10pt !important; min-height: inherit !important; border-collapse: collapse !important;"><tbody style="padding: 0px !important; margin: 0px !important; border: 0px !important; outline: 0px !important; float: none !important; vertical-align: baseline !important; position: static !important; left: auto !important; top: auto !important; right: auto !important; bottom: auto !important; height: auto !important; width: auto !important; line-height: 1.1em !important; font-size: 10pt !important; min-height: inherit !important;"><tr style="padding: 0px !important; margin: 0px !important; border: 0px !important; outline: 0px !important; float: none !important; vertical-align: baseline !important; position: static !important; left: auto !important; top: auto !important; right: auto !important; bottom: auto !important; height: auto !important; width: auto !important; line-height: 1.1em !important; font-size: 10pt !important; min-height: inherit !important;"><td class="number" style="font-family: Consolas, 'Bitstream Vera Sans Mono', 'Courier New', Courier, monospace !important; font-size: 10pt !important; border: 0px !important; padding: 0px !important; margin: 0px !important; outline: 0px !important; float: none !important; vertical-align: top !important; position: static !important; left: auto !important; top: auto !important; right: auto !important; bottom: auto !important; height: auto !important; width: 3em !important; line-height: 1.1em !important; min-height: inherit !important; color: rgb(175, 175, 175) !important;"><code style="padding: 0px 0.3em 0px 0px !important; margin: 0px !important; border: 0px !important; outline: 0px !important; text-align: right !important; float: none !important; vertical-align: baseline !important; position: static !important; left: auto !important; top: auto !important; right: auto !important; bottom: auto !important; height: auto !important; width: 2.7em !important; line-height: 1.1em !important; font-family: Consolas, 'Bitstream Vera Sans Mono', 'Courier New', Courier, monospace !important; font-size: 10pt !important; min-height: inherit !important; display: block !important;"><span style="background-color: rgb(255, 255, 255);">04</span></code></td><td class="content" style="font-family: Consolas, 'Bitstream Vera Sans Mono', 'Courier New', Courier, monospace !important; font-size: 10pt !important; border-width: 0px 0px 0px 3px !important; border-left-style: solid !important; border-left-color: rgb(108, 226, 108) !important; padding: 0px 0px 0px 0.5em !important; margin: 0px !important; outline: 0px !important; float: none !important; vertical-align: top !important; position: static !important; left: auto !important; top: auto !important; right: auto !important; bottom: auto !important; height: auto !important; width: auto !important; line-height: 1.1em !important; min-height: inherit !important;"><code class="comments" style="background-color: rgb(255, 255, 255); padding: 0px !important; margin: 0px !important; border: 0px !important; outline: 0px !important; float: none !important; vertical-align: baseline !important; position: static !important; left: auto !important; top: auto !important; right: auto !important; bottom: auto !important; height: auto !important; width: auto !important; line-height: 1.1em !important; font-family: Consolas, 'Bitstream Vera Sans Mono', 'Courier New', Courier, monospace !important; font-size: 10pt !important; min-height: inherit !important; color: rgb(0, 130, 0) !important;">//方法1.</code></td></tr></tbody></table></div><div class="line alt1" style="padding: 0px !important; margin: 0px !important; border: 0px !important; outline: 0px !important; float: none !important; vertical-align: baseline !important; position: static !important; left: auto !important; top: auto !important; right: auto !important; bottom: auto !important; height: auto !important; width: auto !important; line-height: 1.1em !important; font-family: Consolas, 'Bitstream Vera Sans Mono', 'Courier New', Courier, monospace !important; font-size: 10pt !important; min-height: inherit !important;"><table class=" " style="border: 0px !important; padding: 0px !important; margin: 0px !important; outline: 0px !important; float: none !important; vertical-align: baseline !important; position: static !important; left: auto !important; top: auto !important; right: auto !important; bottom: auto !important; height: auto !important; width: auto !important; line-height: 1.1em !important; font-size: 10pt !important; min-height: inherit !important; border-collapse: collapse !important;"><tbody style="padding: 0px !important; margin: 0px !important; border: 0px !important; outline: 0px !important; float: none !important; vertical-align: baseline !important; position: static !important; left: auto !important; top: auto !important; right: auto !important; bottom: auto !important; height: auto !important; width: auto !important; line-height: 1.1em !important; font-size: 10pt !important; min-height: inherit !important;"><tr style="padding: 0px !important; margin: 0px !important; border: 0px !important; outline: 0px !important; float: none !important; vertical-align: baseline !important; position: static !important; left: auto !important; top: auto !important; right: auto !important; bottom: auto !important; height: auto !important; width: auto !important; line-height: 1.1em !important; font-size: 10pt !important; min-height: inherit !important;"><td class="number" style="font-family: Consolas, 'Bitstream Vera Sans Mono', 'Courier New', Courier, monospace !important; font-size: 10pt !important; border: 0px !important; padding: 0px !important; margin: 0px !important; outline: 0px !important; float: none !important; vertical-align: top !important; position: static !important; left: auto !important; top: auto !important; right: auto !important; bottom: auto !important; height: auto !important; width: 3em !important; line-height: 1.1em !important; min-height: inherit !important; color: rgb(175, 175, 175) !important;"><code style="padding: 0px 0.3em 0px 0px !important; margin: 0px !important; border: 0px !important; outline: 0px !important; text-align: right !important; float: none !important; vertical-align: baseline !important; position: static !important; left: auto !important; top: auto !important; right: auto !important; bottom: auto !important; height: auto !important; width: 2.7em !important; line-height: 1.1em !important; font-family: Consolas, 'Bitstream Vera Sans Mono', 'Courier New', Courier, monospace !important; font-size: 10pt !important; min-height: inherit !important; display: block !important;"><span style="background-color: rgb(255, 255, 255);">05</span></code></td><td class="content" style="font-family: Consolas, 'Bitstream Vera Sans Mono', 'Courier New', Courier, monospace !important; font-size: 10pt !important; border-width: 0px 0px 0px 3px !important; border-left-style: solid !important; border-left-color: rgb(108, 226, 108) !important; padding: 0px 0px 0px 0.5em !important; margin: 0px !important; outline: 0px !important; float: none !important; vertical-align: top !important; position: static !important; left: auto !important; top: auto !important; right: auto !important; bottom: auto !important; height: auto !important; width: auto !important; line-height: 1.1em !important; min-height: inherit !important;"><span style="background-color: rgb(255, 255, 255);"><code class="plain" style="padding: 0px !important; margin: 0px !important; border: 0px !important; outline: 0px !important; float: none !important; vertical-align: baseline !important; position: static !important; left: auto !important; top: auto !important; right: auto !important; bottom: auto !important; height: auto !important; width: auto !important; line-height: 1.1em !important; font-family: Consolas, 'Bitstream Vera Sans Mono', 'Courier New', Courier, monospace !important; font-size: 10pt !important; min-height: inherit !important;">string = [NSString initWithFormat:@</code><code class="string" style="padding: 0px !important; margin: 0px !important; border: 0px !important; outline: 0px !important; float: none !important; vertical-align: baseline !important; position: static !important; left: auto !important; top: auto !important; right: auto !important; bottom: auto !important; height: auto !important; width: auto !important; line-height: 1.1em !important; font-family: Consolas, 'Bitstream Vera Sans Mono', 'Courier New', Courier, monospace !important; font-size: 10pt !important; min-height: inherit !important; color: blue !important;">"%@,%@"</code><code class="plain" style="padding: 0px !important; margin: 0px !important; border: 0px !important; outline: 0px !important; float: none !important; vertical-align: baseline !important; position: static !important; left: auto !important; top: auto !important; right: auto !important; bottom: auto !important; height: auto !important; width: auto !important; line-height: 1.1em !important; font-family: Consolas, 'Bitstream Vera Sans Mono', 'Courier New', Courier, monospace !important; font-size: 10pt !important; min-height: inherit !important;">, string1, string2 ];</code></span></td></tr></tbody></table></div><div class="line alt2" style="padding: 0px !important; margin: 0px !important; border: 0px !important; outline: 0px !important; float: none !important; vertical-align: baseline !important; position: static !important; left: auto !important; top: auto !important; right: auto !important; bottom: auto !important; height: auto !important; width: auto !important; line-height: 1.1em !important; font-family: Consolas, 'Bitstream Vera Sans Mono', 'Courier New', Courier, monospace !important; font-size: 10pt !important; min-height: inherit !important;"><table class=" " style="border: 0px !important; padding: 0px !important; margin: 0px !important; outline: 0px !important; float: none !important; vertical-align: baseline !important; position: static !important; left: auto !important; top: auto !important; right: auto !important; bottom: auto !important; height: auto !important; width: auto !important; line-height: 1.1em !important; font-size: 10pt !important; min-height: inherit !important; border-collapse: collapse !important;"><tbody style="padding: 0px !important; margin: 0px !important; border: 0px !important; outline: 0px !important; float: none !important; vertical-align: baseline !important; position: static !important; left: auto !important; top: auto !important; right: auto !important; bottom: auto !important; height: auto !important; width: auto !important; line-height: 1.1em !important; font-size: 10pt !important; min-height: inherit !important;"><tr style="padding: 0px !important; margin: 0px !important; border: 0px !important; outline: 0px !important; float: none !important; vertical-align: baseline !important; position: static !important; left: auto !important; top: auto !important; right: auto !important; bottom: auto !important; height: auto !important; width: auto !important; line-height: 1.1em !important; font-size: 10pt !important; min-height: inherit !important;"><td class="number" style="font-family: Consolas, 'Bitstream Vera Sans Mono', 'Courier New', Courier, monospace !important; font-size: 10pt !important; border: 0px !important; padding: 0px !important; margin: 0px !important; outline: 0px !important; float: none !important; vertical-align: top !important; position: static !important; left: auto !important; top: auto !important; right: auto !important; bottom: auto !important; height: auto !important; width: 3em !important; line-height: 1.1em !important; min-height: inherit !important; color: rgb(175, 175, 175) !important;"><code style="padding: 0px 0.3em 0px 0px !important; margin: 0px !important; border: 0px !important; outline: 0px !important; text-align: right !important; float: none !important; vertical-align: baseline !important; position: static !important; left: auto !important; top: auto !important; right: auto !important; bottom: auto !important; height: auto !important; width: 2.7em !important; line-height: 1.1em !important; font-family: Consolas, 'Bitstream Vera Sans Mono', 'Courier New', Courier, monospace !important; font-size: 10pt !important; min-height: inherit !important; display: block !important;"><span style="background-color: rgb(255, 255, 255);">06</span></code></td><td class="content" style="font-family: Consolas, 'Bitstream Vera Sans Mono', 'Courier New', Courier, monospace !important; font-size: 10pt !important; border-width: 0px 0px 0px 3px !important; border-left-style: solid !important; border-left-color: rgb(108, 226, 108) !important; padding: 0px 0px 0px 0.5em !important; margin: 0px !important; outline: 0px !important; float: none !important; vertical-align: top !important; position: static !important; left: auto !important; top: auto !important; right: auto !important; bottom: auto !important; height: auto !important; width: auto !important; line-height: 1.1em !important; min-height: inherit !important;"><span style="background-color: rgb(255, 255, 255);">
</span></td></tr></tbody></table></div><div class="line alt1" style="padding: 0px !important; margin: 0px !important; border: 0px !important; outline: 0px !important; float: none !important; vertical-align: baseline !important; position: static !important; left: auto !important; top: auto !important; right: auto !important; bottom: auto !important; height: auto !important; width: auto !important; line-height: 1.1em !important; font-family: Consolas, 'Bitstream Vera Sans Mono', 'Courier New', Courier, monospace !important; font-size: 10pt !important; min-height: inherit !important;"><table class=" " style="border: 0px !important; padding: 0px !important; margin: 0px !important; outline: 0px !important; float: none !important; vertical-align: baseline !important; position: static !important; left: auto !important; top: auto !important; right: auto !important; bottom: auto !important; height: auto !important; width: auto !important; line-height: 1.1em !important; font-size: 10pt !important; min-height: inherit !important; border-collapse: collapse !important;"><tbody style="padding: 0px !important; margin: 0px !important; border: 0px !important; outline: 0px !important; float: none !important; vertical-align: baseline !important; position: static !important; left: auto !important; top: auto !important; right: auto !important; bottom: auto !important; height: auto !important; width: auto !important; line-height: 1.1em !important; font-size: 10pt !important; min-height: inherit !important;"><tr style="padding: 0px !important; margin: 0px !important; border: 0px !important; outline: 0px !important; float: none !important; vertical-align: baseline !important; position: static !important; left: auto !important; top: auto !important; right: auto !important; bottom: auto !important; height: auto !important; width: auto !important; line-height: 1.1em !important; font-size: 10pt !important; min-height: inherit !important;"><td class="number" style="font-family: Consolas, 'Bitstream Vera Sans Mono', 'Courier New', Courier, monospace !important; font-size: 10pt !important; border: 0px !important; padding: 0px !important; margin: 0px !important; outline: 0px !important; float: none !important; vertical-align: top !important; position: static !important; left: auto !important; top: auto !important; right: auto !important; bottom: auto !important; height: auto !important; width: 3em !important; line-height: 1.1em !important; min-height: inherit !important; color: rgb(175, 175, 175) !important;"><code style="padding: 0px 0.3em 0px 0px !important; margin: 0px !important; border: 0px !important; outline: 0px !important; text-align: right !important; float: none !important; vertical-align: baseline !important; position: static !important; left: auto !important; top: auto !important; right: auto !important; bottom: auto !important; height: auto !important; width: 2.7em !important; line-height: 1.1em !important; font-family: Consolas, 'Bitstream Vera Sans Mono', 'Courier New', Courier, monospace !important; font-size: 10pt !important; min-height: inherit !important; display: block !important;"><span style="background-color: rgb(255, 255, 255);">07</span></code></td><td class="content" style="font-family: Consolas, 'Bitstream Vera Sans Mono', 'Courier New', Courier, monospace !important; font-size: 10pt !important; border-width: 0px 0px 0px 3px !important; border-left-style: solid !important; border-left-color: rgb(108, 226, 108) !important; padding: 0px 0px 0px 0.5em !important; margin: 0px !important; outline: 0px !important; float: none !important; vertical-align: top !important; position: static !important; left: auto !important; top: auto !important; right: auto !important; bottom: auto !important; height: auto !important; width: auto !important; line-height: 1.1em !important; min-height: inherit !important;"><code class="comments" style="background-color: rgb(255, 255, 255); padding: 0px !important; margin: 0px !important; border: 0px !important; outline: 0px !important; float: none !important; vertical-align: baseline !important; position: static !important; left: auto !important; top: auto !important; right: auto !important; bottom: auto !important; height: auto !important; width: auto !important; line-height: 1.1em !important; font-family: Consolas, 'Bitstream Vera Sans Mono', 'Courier New', Courier, monospace !important; font-size: 10pt !important; min-height: inherit !important; color: rgb(0, 130, 0) !important;">//方法2.</code></td></tr></tbody></table></div><div class="line alt2" style="padding: 0px !important; margin: 0px !important; border: 0px !important; outline: 0px !important; float: none !important; vertical-align: baseline !important; position: static !important; left: auto !important; top: auto !important; right: auto !important; bottom: auto !important; height: auto !important; width: auto !important; line-height: 1.1em !important; font-family: Consolas, 'Bitstream Vera Sans Mono', 'Courier New', Courier, monospace !important; font-size: 10pt !important; min-height: inherit !important;"><table class=" " style="border: 0px !important; padding: 0px !important; margin: 0px !important; outline: 0px !important; float: none !important; vertical-align: baseline !important; position: static !important; left: auto !important; top: auto !important; right: auto !important; bottom: auto !important; height: auto !important; width: auto !important; line-height: 1.1em !important; font-size: 10pt !important; min-height: inherit !important; border-collapse: collapse !important;"><tbody style="padding: 0px !important; margin: 0px !important; border: 0px !important; outline: 0px !important; float: none !important; vertical-align: baseline !important; position: static !important; left: auto !important; top: auto !important; right: auto !important; bottom: auto !important; height: auto !important; width: auto !important; line-height: 1.1em !important; font-size: 10pt !important; min-height: inherit !important;"><tr style="padding: 0px !important; margin: 0px !important; border: 0px !important; outline: 0px !important; float: none !important; vertical-align: baseline !important; position: static !important; left: auto !important; top: auto !important; right: auto !important; bottom: auto !important; height: auto !important; width: auto !important; line-height: 1.1em !important; font-size: 10pt !important; min-height: inherit !important;"><td class="number" style="font-family: Consolas, 'Bitstream Vera Sans Mono', 'Courier New', Courier, monospace !important; font-size: 10pt !important; border: 0px !important; padding: 0px !important; margin: 0px !important; outline: 0px !important; float: none !important; vertical-align: top !important; position: static !important; left: auto !important; top: auto !important; right: auto !important; bottom: auto !important; height: auto !important; width: 3em !important; line-height: 1.1em !important; min-height: inherit !important; color: rgb(175, 175, 175) !important;"><code style="padding: 0px 0.3em 0px 0px !important; margin: 0px !important; border: 0px !important; outline: 0px !important; text-align: right !important; float: none !important; vertical-align: baseline !important; position: static !important; left: auto !important; top: auto !important; right: auto !important; bottom: auto !important; height: auto !important; width: 2.7em !important; line-height: 1.1em !important; font-family: Consolas, 'Bitstream Vera Sans Mono', 'Courier New', Courier, monospace !important; font-size: 10pt !important; min-height: inherit !important; display: block !important;"><span style="background-color: rgb(255, 255, 255);">08</span></code></td><td class="content" style="font-family: Consolas, 'Bitstream Vera Sans Mono', 'Courier New', Courier, monospace !important; font-size: 10pt !important; border-width: 0px 0px 0px 3px !important; border-left-style: solid !important; border-left-color: rgb(108, 226, 108) !important; padding: 0px 0px 0px 0.5em !important; margin: 0px !important; outline: 0px !important; float: none !important; vertical-align: top !important; position: static !important; left: auto !important; top: auto !important; right: auto !important; bottom: auto !important; height: auto !important; width: auto !important; line-height: 1.1em !important; min-height: inherit !important;"><code class="plain" style="background-color: rgb(255, 255, 255); padding: 0px !important; margin: 0px !important; border: 0px !important; outline: 0px !important; float: none !important; vertical-align: baseline !important; position: static !important; left: auto !important; top: auto !important; right: auto !important; bottom: auto !important; height: auto !important; width: auto !important; line-height: 1.1em !important; font-family: Consolas, 'Bitstream Vera Sans Mono', 'Courier New', Courier, monospace !important; font-size: 10pt !important; min-height: inherit !important;">string = [string1 stringByAppendingString:string2];</code></td></tr></tbody></table></div><div class="line alt1" style="padding: 0px !important; margin: 0px !important; border: 0px !important; outline: 0px !important; float: none !important; vertical-align: baseline !important; position: static !important; left: auto !important; top: auto !important; right: auto !important; bottom: auto !important; height: auto !important; width: auto !important; line-height: 1.1em !important; font-family: Consolas, 'Bitstream Vera Sans Mono', 'Courier New', Courier, monospace !important; font-size: 10pt !important; min-height: inherit !important;"><table class=" " style="border: 0px !important; padding: 0px !important; margin: 0px !important; outline: 0px !important; float: none !important; vertical-align: baseline !important; position: static !important; left: auto !important; top: auto !important; right: auto !important; bottom: auto !important; height: auto !important; width: auto !important; line-height: 1.1em !important; font-size: 10pt !important; min-height: inherit !important; border-collapse: collapse !important;"><tbody style="padding: 0px !important; margin: 0px !important; border: 0px !important; outline: 0px !important; float: none !important; vertical-align: baseline !important; position: static !important; left: auto !important; top: auto !important; right: auto !important; bottom: auto !important; height: auto !important; width: auto !important; line-height: 1.1em !important; font-size: 10pt !important; min-height: inherit !important;"><tr style="padding: 0px !important; margin: 0px !important; border: 0px !important; outline: 0px !important; float: none !important; vertical-align: baseline !important; position: static !important; left: auto !important; top: auto !important; right: auto !important; bottom: auto !important; height: auto !important; width: auto !important; line-height: 1.1em !important; font-size: 10pt !important; min-height: inherit !important;"><td class="number" style="font-family: Consolas, 'Bitstream Vera Sans Mono', 'Courier New', Courier, monospace !important; font-size: 10pt !important; border: 0px !important; padding: 0px !important; margin: 0px !important; outline: 0px !important; float: none !important; vertical-align: top !important; position: static !important; left: auto !important; top: auto !important; right: auto !important; bottom: auto !important; height: auto !important; width: 3em !important; line-height: 1.1em !important; min-height: inherit !important; color: rgb(175, 175, 175) !important;"><code style="padding: 0px 0.3em 0px 0px !important; margin: 0px !important; border: 0px !important; outline: 0px !important; text-align: right !important; float: none !important; vertical-align: baseline !important; position: static !important; left: auto !important; top: auto !important; right: auto !important; bottom: auto !important; height: auto !important; width: 2.7em !important; line-height: 1.1em !important; font-family: Consolas, 'Bitstream Vera Sans Mono', 'Courier New', Courier, monospace !important; font-size: 10pt !important; min-height: inherit !important; display: block !important;"><span style="background-color: rgb(255, 255, 255);">09</span></code></td><td class="content" style="font-family: Consolas, 'Bitstream Vera Sans Mono', 'Courier New', Courier, monospace !important; font-size: 10pt !important; border-width: 0px 0px 0px 3px !important; border-left-style: solid !important; border-left-color: rgb(108, 226, 108) !important; padding: 0px 0px 0px 0.5em !important; margin: 0px !important; outline: 0px !important; float: none !important; vertical-align: top !important; position: static !important; left: auto !important; top: auto !important; right: auto !important; bottom: auto !important; height: auto !important; width: auto !important; line-height: 1.1em !important; min-height: inherit !important;"><span style="background-color: rgb(255, 255, 255);">
</span></td></tr></tbody></table></div><div class="line alt2" style="padding: 0px !important; margin: 0px !important; border: 0px !important; outline: 0px !important; float: none !important; vertical-align: baseline !important; position: static !important; left: auto !important; top: auto !important; right: auto !important; bottom: auto !important; height: auto !important; width: auto !important; line-height: 1.1em !important; font-family: Consolas, 'Bitstream Vera Sans Mono', 'Courier New', Courier, monospace !important; font-size: 10pt !important; min-height: inherit !important;"><table class=" " style="border: 0px !important; padding: 0px !important; margin: 0px !important; outline: 0px !important; float: none !important; vertical-align: baseline !important; position: static !important; left: auto !important; top: auto !important; right: auto !important; bottom: auto !important; height: auto !important; width: auto !important; line-height: 1.1em !important; font-size: 10pt !important; min-height: inherit !important; border-collapse: collapse !important;"><tbody style="padding: 0px !important; margin: 0px !important; border: 0px !important; outline: 0px !important; float: none !important; vertical-align: baseline !important; position: static !important; left: auto !important; top: auto !important; right: auto !important; bottom: auto !important; height: auto !important; width: auto !important; line-height: 1.1em !important; font-size: 10pt !important; min-height: inherit !important;"><tr style="padding: 0px !important; margin: 0px !important; border: 0px !important; outline: 0px !important; float: none !important; vertical-align: baseline !important; position: static !important; left: auto !important; top: auto !important; right: auto !important; bottom: auto !important; height: auto !important; width: auto !important; line-height: 1.1em !important; font-size: 10pt !important; min-height: inherit !important;"><td class="number" style="font-family: Consolas, 'Bitstream Vera Sans Mono', 'Courier New', Courier, monospace !important; font-size: 10pt !important; border: 0px !important; padding: 0px !important; margin: 0px !important; outline: 0px !important; float: none !important; vertical-align: top !important; position: static !important; left: auto !important; top: auto !important; right: auto !important; bottom: auto !important; height: auto !important; width: 3em !important; line-height: 1.1em !important; min-height: inherit !important; color: rgb(175, 175, 175) !important;"><code style="padding: 0px 0.3em 0px 0px !important; margin: 0px !important; border: 0px !important; outline: 0px !important; text-align: right !important; float: none !important; vertical-align: baseline !important; position: static !important; left: auto !important; top: auto !important; right: auto !important; bottom: auto !important; height: auto !important; width: 2.7em !important; line-height: 1.1em !important; font-family: Consolas, 'Bitstream Vera Sans Mono', 'Courier New', Courier, monospace !important; font-size: 10pt !important; min-height: inherit !important; display: block !important;"><span style="background-color: rgb(255, 255, 255);">10</span></code></td><td class="content" style="font-family: Consolas, 'Bitstream Vera Sans Mono', 'Courier New', Courier, monospace !important; font-size: 10pt !important; border-width: 0px 0px 0px 3px !important; border-left-style: solid !important; border-left-color: rgb(108, 226, 108) !important; padding: 0px 0px 0px 0.5em !important; margin: 0px !important; outline: 0px !important; float: none !important; vertical-align: top !important; position: static !important; left: auto !important; top: auto !important; right: auto !important; bottom: auto !important; height: auto !important; width: auto !important; line-height: 1.1em !important; min-height: inherit !important;"><code class="comments" style="background-color: rgb(255, 255, 255); padding: 0px !important; margin: 0px !important; border: 0px !important; outline: 0px !important; float: none !important; vertical-align: baseline !important; position: static !important; left: auto !important; top: auto !important; right: auto !important; bottom: auto !important; height: auto !important; width: auto !important; line-height: 1.1em !important; font-family: Consolas, 'Bitstream Vera Sans Mono', 'Courier New', Courier, monospace !important; font-size: 10pt !important; min-height: inherit !important; color: rgb(0, 130, 0) !important;">//方法3 .</code></td></tr></tbody></table></div><div class="line alt1" style="padding: 0px !important; margin: 0px !important; border: 0px !important; outline: 0px !important; float: none !important; vertical-align: baseline !important; position: static !important; left: auto !important; top: auto !important; right: auto !important; bottom: auto !important; height: auto !important; width: auto !important; line-height: 1.1em !important; font-family: Consolas, 'Bitstream Vera Sans Mono', 'Courier New', Courier, monospace !important; font-size: 10pt !important; min-height: inherit !important;"><table class=" " style="border: 0px !important; padding: 0px !important; margin: 0px !important; outline: 0px !important; float: none !important; vertical-align: baseline !important; position: static !important; left: auto !important; top: auto !important; right: auto !important; bottom: auto !important; height: auto !important; width: auto !important; line-height: 1.1em !important; font-size: 10pt !important; min-height: inherit !important; border-collapse: collapse !important;"><tbody style="padding: 0px !important; margin: 0px !important; border: 0px !important; outline: 0px !important; float: none !important; vertical-align: baseline !important; position: static !important; left: auto !important; top: auto !important; right: auto !important; bottom: auto !important; height: auto !important; width: auto !important; line-height: 1.1em !important; font-size: 10pt !important; min-height: inherit !important;"><tr style="padding: 0px !important; margin: 0px !important; border: 0px !important; outline: 0px !important; float: none !important; vertical-align: baseline !important; position: static !important; left: auto !important; top: auto !important; right: auto !important; bottom: auto !important; height: auto !important; width: auto !important; line-height: 1.1em !important; font-size: 10pt !important; min-height: inherit !important;"><td class="number" style="font-family: Consolas, 'Bitstream Vera Sans Mono', 'Courier New', Courier, monospace !important; font-size: 10pt !important; border: 0px !important; padding: 0px !important; margin: 0px !important; outline: 0px !important; float: none !important; vertical-align: top !important; position: static !important; left: auto !important; top: auto !important; right: auto !important; bottom: auto !important; height: auto !important; width: 3em !important; line-height: 1.1em !important; min-height: inherit !important; color: rgb(175, 175, 175) !important;"><code style="padding: 0px 0.3em 0px 0px !important; margin: 0px !important; border: 0px !important; outline: 0px !important; text-align: right !important; float: none !important; vertical-align: baseline !important; position: static !important; left: auto !important; top: auto !important; right: auto !important; bottom: auto !important; height: auto !important; width: 2.7em !important; line-height: 1.1em !important; font-family: Consolas, 'Bitstream Vera Sans Mono', 'Courier New', Courier, monospace !important; font-size: 10pt !important; min-height: inherit !important; display: block !important;"><span style="background-color: rgb(255, 255, 255);">11</span></code></td><td class="content" style="font-family: Consolas, 'Bitstream Vera Sans Mono', 'Courier New', Courier, monospace !important; font-size: 10pt !important; border-width: 0px 0px 0px 3px !important; border-left-style: solid !important; border-left-color: rgb(108, 226, 108) !important; padding: 0px 0px 0px 0.5em !important; margin: 0px !important; outline: 0px !important; float: none !important; vertical-align: top !important; position: static !important; left: auto !important; top: auto !important; right: auto !important; bottom: auto !important; height: auto !important; width: auto !important; line-height: 1.1em !important; min-height: inherit !important;"><span style="background-color: rgb(255, 255, 255);"><code class="plain" style="padding: 0px !important; margin: 0px !important; border: 0px !important; outline: 0px !important; float: none !important; vertical-align: baseline !important; position: static !important; left: auto !important; top: auto !important; right: auto !important; bottom: auto !important; height: auto !important; width: auto !important; line-height: 1.1em !important; font-family: Consolas, 'Bitstream Vera Sans Mono', 'Courier New', Courier, monospace !important; font-size: 10pt !important; min-height: inherit !important;">string = [string stringByAppendingFormat:@</code><code class="string" style="padding: 0px !important; margin: 0px !important; border: 0px !important; outline: 0px !important; float: none !important; vertical-align: baseline !important; position: static !important; left: auto !important; top: auto !important; right: auto !important; bottom: auto !important; height: auto !important; width: auto !important; line-height: 1.1em !important; font-family: Consolas, 'Bitstream Vera Sans Mono', 'Courier New', Courier, monospace !important; font-size: 10pt !important; min-height: inherit !important; color: blue !important;">"%@,%@"</code><code class="plain" style="padding: 0px !important; margin: 0px !important; border: 0px !important; outline: 0px !important; float: none !important; vertical-align: baseline !important; position: static !important; left: auto !important; top: auto !important; right: auto !important; bottom: auto !important; height: auto !important; width: auto !important; line-height: 1.1em !important; font-family: Consolas, 'Bitstream Vera Sans Mono', 'Courier New', Courier, monospace !important; font-size: 10pt !important; min-height: inherit !important;">,string1, string2];</code></span></td></tr></tbody></table><span style="background-color: rgb(255, 255, 255);">
</span></div><div class="line alt1" style="padding: 0px !important; margin: 0px !important; border: 0px !important; outline: 0px !important; float: none !important; vertical-align: baseline !important; position: static !important; left: auto !important; top: auto !important; right: auto !important; bottom: auto !important; height: auto !important; width: auto !important; line-height: 1.1em !important; font-family: Consolas, 'Bitstream Vera Sans Mono', 'Courier New', Courier, monospace !important; font-size: 10pt !important; min-height: inherit !important;"><span style="background-color: rgb(255, 255, 255);">经常用的是第二种方法。</span></div><span style="background-color: rgb(255, 255, 255);">
</span><div style="color: rgb(50, 62, 50); font-family: simsun; line-height: 21px; text-indent: 2em;"><span style="background-color: rgb(255, 255, 255);">PS：自己根据每段学习阶段的学习情况写的笔记，都是基本的内容，可能会有错误，仅供参考！</span></div><div style="color: rgb(50, 62, 50); font-family: simsun; line-height: 21px; text-indent: 2em;"><span style="background-color: rgb(255, 255, 255);">
</span></div><span style="color: rgb(50, 62, 50); font-family: simsun; line-height: 21px; text-indent: 28px; background-color: rgb(255, 255, 255);">在Object-c中，字符串的声明是：</span><div style="color: rgb(50, 62, 50); font-family: simsun; line-height: 21px; text-indent: 28px;"><span style="word-wrap: normal; word-break: normal; line-height: 25px; font-family: 'Microsoft YaHei', Tahoma, Helvetica, simsun, sans-serif; background-color: rgb(255, 255, 255);">NSString *aString; <wbr></wbr></span></div><div style="color: rgb(50, 62, 50); font-family: simsun; line-height: 21px; text-indent: 28px;"><span style="word-wrap: normal; word-break: normal; line-height: 25px; font-family: 'Microsoft YaHei', Tahoma, Helvetica, simsun, sans-serif; background-color: rgb(255, 255, 255);">aString并不真正包含一个字符串对象—它是指向内存中字符串对象的指针。(和C语言中，用指针指向字符串的声明类似)；</span></div><div style="color: rgb(50, 62, 50); font-family: simsun; line-height: 21px; text-indent: 28px;"><ul style="margin: 0px; padding: 0px; border: 0px; list-style: none;"><li style="margin: 0px 0px 0px 30px; padding: 0px; border: 0px; list-style: disc;"><span style="word-wrap: normal; word-break: normal; line-height: 25px; font-family: 'Microsoft YaHei', Tahoma, Helvetica, simsun, sans-serif; text-indent: 2em; background-color: rgb(255, 255, 255);">字符串声明，以下三种方法：</span></li></ul></div><div style="color: rgb(50, 62, 50); font-family: simsun; line-height: 21px; text-indent: 28px;"><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal;"><span style="background-color: rgb(255, 255, 255);"><span style="word-wrap: normal; word-break: normal;">NSString</span><span style="word-wrap: normal; word-break: normal;"> <wbr>*a0 = [[</wbr></span><span style="word-wrap: normal; word-break: normal;">NSString</span><span style="word-wrap: normal; word-break: normal;"> <wbr></wbr></span>alloc<span style="word-wrap: normal; word-break: normal;">]</span>initWithFormat<span style="word-wrap: normal; word-break: normal;">:</span><span style="word-wrap: normal; word-break: normal;">@"kevin"</span><span style="word-wrap: normal; word-break: normal;">]; <wbr> <wbr> <wbr>//方法一</wbr></wbr></wbr></span></span></p><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal;"><span style="background-color: rgb(255, 255, 255);"> <wbr></wbr></span></p><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal; line-height: 25px; font-family: 'Microsoft YaHei', Tahoma, Helvetica, simsun, sans-serif;"><span style="background-color: rgb(255, 255, 255);"><span style="word-wrap: normal; word-break: normal; line-height: 21px;">NSString</span><span style="word-wrap: normal; word-break: normal; line-height: 21px;"> <wbr>*a1 = [[</wbr></span><span style="word-wrap: normal; word-break: normal; line-height: 21px;">NSString</span><span style="word-wrap: normal; word-break: normal; line-height: 21px;"> <wbr></wbr></span>alloc<span style="word-wrap: normal; word-break: normal; line-height: 21px;">]</span>initWithString<span style="word-wrap: normal; word-break: normal; line-height: 21px;">:</span><span style="word-wrap: normal; word-break: normal; line-height: 21px;">@"kevin"</span><span style="word-wrap: normal; word-break: normal; line-height: 21px;">]; <wbr> <wbr>//方法二</wbr></wbr></span></span></p><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal; line-height: 25px; font-family: 'Microsoft YaHei', Tahoma, Helvetica, simsun, sans-serif;"><span style="background-color: rgb(255, 255, 255);"> <wbr></wbr></span></p><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal; line-height: 25px; font-family: 'Microsoft YaHei', Tahoma, Helvetica, simsun, sans-serif;"><span style="background-color: rgb(255, 255, 255);">NSString<span style="word-wrap: normal; word-break: normal; line-height: 21px;"> <wbr>*a2 = <wbr></wbr></wbr></span><span style="word-wrap: normal; word-break: normal; line-height: 21px;">@"kevin"</span><span style="word-wrap: normal; word-break: normal; line-height: 21px;">; <wbr> <wbr>//方法三</wbr></wbr></span></span></p><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal; line-height: 25px; font-family: 'Microsoft YaHei', Tahoma, Helvetica, simsun, sans-serif;"><span style="word-wrap: normal; word-break: normal; line-height: 21px; background-color: rgb(255, 255, 255);"><span style="word-wrap: normal; word-break: normal;">NSString</span><span style="word-wrap: normal; word-break: normal;"> <wbr>*a3 = [[</wbr></span><span style="word-wrap: normal; word-break: normal;">NSString</span><span style="word-wrap: normal; word-break: normal;"> <wbr></wbr></span><span style="word-wrap: normal; word-break: normal;">alloc</span><span style="word-wrap: normal; word-break: normal;">]</span><span style="word-wrap: normal; word-break: normal;">initWithFormat</span><span style="word-wrap: normal; word-break: normal;">:</span><span style="word-wrap: normal; word-break: normal;">@"kevin"</span><span style="word-wrap: normal; word-break: normal;">]; <wbr></wbr></span></span></p><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal; line-height: 25px; font-family: 'Microsoft YaHei', Tahoma, Helvetica, simsun, sans-serif;"><span style="background-color: rgb(255, 255, 255);">区别1：方法一用Format进行字符串的声明，方法二用String方法声明，第三种方法和用String声明基本一致，但是不初始化内存空间，方法一和方法二中，a0和a1使用结束后，需要进行内存释放，但是a2不需要进行内存释放。</span></p><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal; line-height: 25px; font-family: 'Microsoft YaHei', Tahoma, Helvetica, simsun, sans-serif;"><span style="background-color: rgb(255, 255, 255);">区别2：用Format初始化的字符串，需要初始化一段动态内存空间，如：<strong>0x6a42a40，</strong>而用String声明的字符串，初始化的是常量内存区，如：<strong>0x46a8</strong>，常量内存区的地址，只要值相同，占用的地址空间是一致的。所以a1和a2的地址一致，但是a0和a3的地址不一致。</span></p><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal; line-height: 25px; font-family: 'Microsoft YaHei', Tahoma, Helvetica, simsun, sans-serif;"><span style="background-color: rgb(255, 255, 255);"> <wbr></wbr></span></p><ul style="margin: 0px; padding: 0px; border: 0px; list-style: none;"><li style="margin: 0px 0px 0px 30px; padding: 0px; border: 0px; list-style: disc;"><span style="word-wrap: normal; word-break: normal; line-height: 25px; font-family: 'Microsoft YaHei', Tahoma, Helvetica, simsun, sans-serif; text-indent: 2em; background-color: rgb(255, 255, 255);">将其它类型转化成字符串：</span></li></ul><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal; line-height: 25px; font-family: 'Microsoft YaHei', Tahoma, Helvetica, simsun, sans-serif;"><span style="background-color: rgb(255, 255, 255);">可以使用Format，以整型为例，如：</span></p><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal; line-height: 25px; font-family: 'Microsoft YaHei', Tahoma, Helvetica, simsun, sans-serif;"><span style="background-color: rgb(255, 255, 255);">int i = 100；</span></p><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal; line-height: 25px; font-family: 'Microsoft YaHei', Tahoma, Helvetica, simsun, sans-serif;"><span style="background-color: rgb(255, 255, 255);"><span style="word-wrap: normal; word-break: normal; line-height: 21px;">NSString</span><span style="word-wrap: normal; word-break: normal; line-height: 21px;"> <wbr>*b = [[</wbr></span><span style="word-wrap: normal; word-break: normal; line-height: 21px;">NSString</span><span style="word-wrap: normal; word-break: normal; line-height: 21px;"> <wbr></wbr></span><span style="word-wrap: normal; word-break: normal; line-height: 21px;">alloc</span><span style="word-wrap: normal; word-break: normal; line-height: 21px;">]</span><span style="word-wrap: normal; word-break: normal; line-height: 21px;">initWithFormat</span><span style="word-wrap: normal; word-break: normal; line-height: 21px;">:</span><span style="word-wrap: normal; word-break: normal; line-height: 21px;">@"%d",i</span><span style="word-wrap: normal; word-break: normal; line-height: 21px;">]; <wbr>//如果是float型，可以用%f</wbr></span></span></p><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal; line-height: 25px; font-family: 'Microsoft YaHei', Tahoma, Helvetica, simsun, sans-serif;"><span style="word-wrap: normal; word-break: normal; line-height: 21px; background-color: rgb(255, 255, 255);"><span style="word-wrap: normal; word-break: normal; text-indent: 2em;">NSLog</span><span style="word-wrap: normal; word-break: normal; text-indent: 2em;">(</span><span style="word-wrap: normal; word-break: normal; text-indent: 2em;">@"b = %@"</span><span style="word-wrap: normal; word-break: normal; text-indent: 2em;">,[b</span> <span style="word-wrap: normal; word-break: normal; text-indent: 2em;">description</span><span style="word-wrap: normal; word-break: normal; text-indent: 2em;">]);</span></span></p><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal; line-height: 25px; font-family: 'Microsoft YaHei', Tahoma, Helvetica, simsun, sans-serif;"><span style="word-wrap: normal; word-break: normal; line-height: 21px; background-color: rgb(255, 255, 255);">结果输出：b = 100 <wbr></wbr></span></p><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal; line-height: 25px; font-family: 'Microsoft YaHei', Tahoma, Helvetica, simsun, sans-serif;"><span style="background-color: rgb(255, 255, 255);"> <wbr></wbr></span></p><ul style="margin: 0px; padding: 0px; border: 0px; list-style: none;"><li style="margin: 0px 0px 0px 30px; padding: 0px; border: 0px; list-style: disc;"><span style="word-wrap: normal; word-break: normal; line-height: 25px; font-family: 'Microsoft YaHei', Tahoma, Helvetica, simsun, sans-serif; text-indent: 2em; background-color: rgb(255, 255, 255);">求字符串长度：</span></li></ul><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal; line-height: 25px; font-family: 'Microsoft YaHei', Tahoma, Helvetica, simsun, sans-serif;"><span style="word-wrap: normal; word-break: normal; text-indent: 2em; background-color: rgb(255, 255, 255);">用length求字符串长度，如：</span></p><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal;"><span style="background-color: rgb(255, 255, 255);"> <wbr></wbr></span></p><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal; line-height: 25px; font-family: 'Microsoft YaHei', Tahoma, Helvetica, simsun, sans-serif;"><span style="background-color: rgb(255, 255, 255);"><span style="word-wrap: normal; word-break: normal; line-height: 21px;">NSLog</span><span style="word-wrap: normal; word-break: normal; line-height: 21px;">(</span>@"a1 = %d"<span style="word-wrap: normal; word-break: normal; line-height: 21px;">,a1.</span><span style="word-wrap: normal; word-break: normal; line-height: 21px;">length</span><span style="word-wrap: normal; word-break: normal; line-height: 21px;">);</span></span></p><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal; line-height: 25px; font-family: 'Microsoft YaHei', Tahoma, Helvetica, simsun, sans-serif;"><span style="word-wrap: normal; word-break: normal; line-height: 21px; background-color: rgb(255, 255, 255);">结果输出a1 = 5</span></p><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal;"><span style="background-color: rgb(255, 255, 255);">注意这里和C语言的不同，C语言中，字符串的结束是以'\0'结束，而OC不是。</span></p><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal;"><span style="background-color: rgb(255, 255, 255);"> <wbr></wbr></span></p><ul style="margin: 0px; padding: 0px; border: 0px; list-style: none;"><li style="margin: 0px 0px 0px 30px; padding: 0px; border: 0px; list-style: disc;"><span style="word-wrap: normal; word-break: normal; text-indent: 2em; background-color: rgb(255, 255, 255);">拼接、求子字符串：</span></li></ul><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal;"><span style="background-color: rgb(255, 255, 255);">拼接，使用<span style="word-wrap: normal; word-break: normal; text-indent: 2em;">stringByAppendingString，如：</span></span></p><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal;"><span style="background-color: rgb(255, 255, 255);"><span style="word-wrap: normal; word-break: normal; line-height: 25px; font-family: 'Microsoft YaHei', Tahoma, Helvetica, simsun, sans-serif;">NSString</span><span style="word-wrap: normal; word-break: normal;"> <wbr>*a4 = <wbr></wbr></wbr></span><span style="word-wrap: normal; word-break: normal;">@"2012"</span><span style="word-wrap: normal; word-break: normal;">; <wbr></wbr></span></span></p><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal;"><span style="background-color: rgb(255, 255, 255);"> <wbr></wbr></span></p><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal;"><span style="background-color: rgb(255, 255, 255);"><span style="word-wrap: normal; word-break: normal;">NSString</span> <span style="word-wrap: normal; word-break: normal;">*c = [a0 <wbr></wbr></span>stringByAppendingString<span style="word-wrap: normal; word-break: normal;">:a4];</span></span></p></div><div style="color: rgb(50, 62, 50); font-family: simsun; line-height: 21px; text-indent: 28px;"><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal;"><span style="background-color: rgb(255, 255, 255);"> <wbr></wbr></span></p><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal;"><span style="background-color: rgb(255, 255, 255);"> <wbr></wbr></span></p><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal;"><span style="background-color: rgb(255, 255, 255);"> <wbr></wbr></span></p><div><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal;"><span style="background-color: rgb(255, 255, 255);"><span style="word-wrap: normal; word-break: normal;">NSLog</span><span style="word-wrap: normal; word-break: normal;">(</span>@"c = %@"<span style="word-wrap: normal; word-break: normal;">,c);</span></span></p><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal;"><span style="background-color: rgb(255, 255, 255);">结果输出：c = kevin2012</span></p><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal;"><span style="background-color: rgb(255, 255, 255);">求子字符串，有三种方式：</span></p><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal;"><span style="background-color: rgb(255, 255, 255);"> <wbr></wbr></span></p><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal;"><span style="background-color: rgb(255, 255, 255);">1、substringFromIndex:x <wbr> <wbr>//从索引x开始到结束，包含索引x指向的值（索引的理解有点像C语言中数组的下标）</wbr></wbr></span></p><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal;"><span style="background-color: rgb(255, 255, 255);"> <wbr></wbr></span></p><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal;"><span style="background-color: rgb(255, 255, 255);">2、substringToIndex:x <wbr> <wbr>//从开始到索引x之前结束，不包含索引x指向的值</wbr></wbr></span></p><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal;"><span style="background-color: rgb(255, 255, 255);"> <wbr></wbr></span></p><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal;"><span style="background-color: rgb(255, 255, 255);">3、substringWithRange <wbr> <wbr>//定义一个区间，有开始位置和截取长度</wbr></wbr></span></p><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal;"><span style="background-color: rgb(255, 255, 255);">如下：</span></p><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal;"><span style="background-color: rgb(255, 255, 255);"> <wbr></wbr></span></p><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal;"><span style="background-color: rgb(255, 255, 255);"><span style="word-wrap: normal; word-break: normal;">NSString</span> <span style="word-wrap: normal; word-break: normal;">*d = [a1 <wbr></wbr></span>substringFromIndex<span style="word-wrap: normal; word-break: normal;">:</span><span style="word-wrap: normal; word-break: normal;">1</span><span style="word-wrap: normal; word-break: normal;">];</span></span></p><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal;"><span style="background-color: rgb(255, 255, 255);"> <wbr></wbr></span></p><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal;"><span style="word-wrap: normal; word-break: normal; background-color: rgb(255, 255, 255);"><span style="word-wrap: normal; word-break: normal;">NSString</span> <span style="word-wrap: normal; word-break: normal;">*e = [a1 <wbr></wbr></span>substringToIndex<span style="word-wrap: normal; word-break: normal;">:3</span><span style="word-wrap: normal; word-break: normal;">];</span></span></p></div><div><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal;"><span style="background-color: rgb(255, 255, 255);"><span style="word-wrap: normal; word-break: normal;">NSLog</span><span style="word-wrap: normal; word-break: normal;">(</span>@"d = %@,e = %@"<span style="word-wrap: normal; word-break: normal;">,d,e);</span></span></p><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal;"><span style="background-color: rgb(255, 255, 255);">结果输出为：d = evin,e = kev</span></p><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal;"><span style="word-wrap: normal; word-break: normal; background-color: rgb(255, 255, 255);">substringWithRange先定义区间，如下：
</span></p><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal;"><span style="background-color: rgb(255, 255, 255);"> <wbr></wbr></span></p><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal;"><span style="background-color: rgb(255, 255, 255);"><span style="word-wrap: normal; word-break: normal;">NSRange</span> r = {<span style="word-wrap: normal; word-break: normal;">2</span>,3}; <wbr> <wbr> <wbr>//从索引2开始，截取3个长度</wbr></wbr></wbr></span></p><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal;"><span style="background-color: rgb(255, 255, 255);"> <wbr></wbr></span></p><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal;"><span style="background-color: rgb(255, 255, 255);"><span style="word-wrap: normal; word-break: normal;">NSString</span> <span style="word-wrap: normal; word-break: normal;">*f = [c</span> substringWithRange<span style="word-wrap: normal; word-break: normal;">:r];</span></span></p><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal;"><span style="background-color: rgb(255, 255, 255);"><span style="word-wrap: normal; word-break: normal;">NSLog</span><span style="word-wrap: normal; word-break: normal;">(</span>@"f = %@"<span style="word-wrap: normal; word-break: normal;">,f);</span></span></p><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal;"><span style="background-color: rgb(255, 255, 255);">结果输出为：f = vin</span></p><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal;"><span style="background-color: rgb(255, 255, 255);"> <wbr></wbr></span></p><ul style="margin: 0px; padding: 0px; border: 0px; list-style: none;"><li style="margin: 0px 0px 0px 30px; padding: 0px; border: 0px; list-style: disc;"><span style="word-wrap: normal; word-break: normal; text-indent: 2em; background-color: rgb(255, 255, 255);">字符串转化成其它类型：</span></li></ul><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal;"><span style="background-color: rgb(255, 255, 255);"> <wbr></wbr></span></p><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal;"><span style="background-color: rgb(255, 255, 255);"><span style="word-wrap: normal; word-break: normal;">int</span> j = [a4 <wbr><span style="word-wrap: normal; word-break: normal;">intValue</span>]; <wbr> <wbr>//如果字符串由数字开头，转化为起始的数字，否则转化为0</wbr></wbr></wbr></span></p><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal;"><span style="background-color: rgb(255, 255, 255);"> <wbr></wbr></span></p><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal;"><span style="background-color: rgb(255, 255, 255);"><span style="word-wrap: normal; word-break: normal;">NSLog</span><span style="word-wrap: normal; word-break: normal;">(</span>@"j = %d"<span style="word-wrap: normal; word-break: normal;">,j);</span></span></p><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal;"><span style="background-color: rgb(255, 255, 255);">还可以转化为float，BOOL型，查文档得知，如果转化为BOOL型，<span style="word-wrap: normal; word-break: normal; text-indent: 2em;">Returns YES on encountering one of "Y", "y", "T", "t", or a digit 1-9—the method ignores any trailing characters. Returns NO if the receiver doesn’t begin with a valid decimal text representation of a number.（由Y,y,T,t,1-9开始的字符串转化为YES，其余的为NO）</span></span></p><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal;"><span style="background-color: rgb(255, 255, 255);"> <wbr></wbr></span></p><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal;"><span style="background-color: rgb(255, 255, 255);"> <wbr></wbr></span></p><ul style="margin: 0px; padding: 0px; border: 0px; list-style: none;"><li style="margin: 0px 0px 0px 30px; padding: 0px; border: 0px; list-style: disc;"><span style="word-wrap: normal; word-break: normal; text-indent: 2em; background-color: rgb(255, 255, 255);">比较字符串是否相等：</span></li></ul><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal;"><span style="background-color: rgb(255, 255, 255);"> <wbr></wbr></span></p><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal;"><span style="background-color: rgb(255, 255, 255);">a0 isEqual:(id) <wbr> //<span style="word-wrap: normal; word-break: normal; text-indent: 2em;">a</span><span style="word-wrap: normal; word-break: normal; text-indent: 2em;">和一个对象进行判断，比较的是地址</span><span style="word-wrap: normal; word-break: normal; text-indent: 2em;">,</span><span style="word-wrap: normal; word-break: normal; text-indent: 2em;">如果发现传进来的都是字符串，直接比较字符串大小，若相等，就返回</span><span style="word-wrap: normal; word-break: normal; text-indent: 2em;">YES</span><span style="word-wrap: normal; word-break: normal; text-indent: 2em;">，如果不是字符串，就进行地址比较</span></wbr></span></p><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal;"><span style="background-color: rgb(255, 255, 255);"> <wbr></wbr></span></p><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal;"><span style="background-color: rgb(255, 255, 255);">a0 isEqualToString:b <wbr> <wbr>//<span style="word-wrap: normal; word-break: normal; text-indent: 2em;">a</span><span style="word-wrap: normal; word-break: normal; text-indent: 2em;">和字符串</span><span style="word-wrap: normal; word-break: normal; text-indent: 2em;">b</span><span style="word-wrap: normal; word-break: normal; text-indent: 2em;">进行比较，比较字符串大小</span></wbr></wbr></span></p><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal;"><span style="background-color: rgb(255, 255, 255);">如下：</span></p><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal;"><span style="background-color: rgb(255, 255, 255);"> <wbr></wbr></span></p><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal;"><span style="background-color: rgb(255, 255, 255);"><span style="word-wrap: normal; word-break: normal;">BOOL</span> c1 = [<span style="word-wrap: normal; word-break: normal;">@"12"</span> <span style="word-wrap: normal; word-break: normal;">isEqual</span>:<span style="word-wrap: normal; word-break: normal;">@"12"</span>];</span></p><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal;"><span style="background-color: rgb(255, 255, 255);"><span style="word-wrap: normal; word-break: normal;">BOOL</span> <span style="word-wrap: normal; word-break: normal;">c2 = [</span><span style="word-wrap: normal; word-break: normal;">@"12"</span> isEqualToString<span style="word-wrap: normal; word-break: normal;">:</span><span style="word-wrap: normal; word-break: normal;">@"12"</span><span style="word-wrap: normal; word-break: normal;">];</span></span></p><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal;"><span style="background-color: rgb(255, 255, 255);"> <wbr></wbr></span></p><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal;"><span style="word-wrap: normal; word-break: normal; background-color: rgb(255, 255, 255);"><span style="word-wrap: normal; word-break: normal;">BOOL</span> <span style="word-wrap: normal; word-break: normal;">c3 = [</span><span style="word-wrap: normal; word-break: normal;">a0</span> isEqualToString<span style="word-wrap: normal; word-break: normal;">:a1</span><span style="word-wrap: normal; word-break: normal;">];</span></span></p><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal;"><span style="background-color: rgb(255, 255, 255);"> <wbr></wbr></span></p><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal;"><span style="word-wrap: normal; word-break: normal; background-color: rgb(255, 255, 255);"><span style="word-wrap: normal; word-break: normal;">NSLog</span><span style="word-wrap: normal; word-break: normal;">(</span>@"c1 = %d,c2 = %d,c3 = %d"<span style="word-wrap: normal; word-break: normal;">,c1,c2,c3);</span></span></p><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal;"><span style="background-color: rgb(255, 255, 255);">结果输出为：c1 = 1,c2 = 1,c3 = 0;</span></p><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal;"><span style="background-color: rgb(255, 255, 255);"> <wbr></wbr></span></p><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal;"><span style="background-color: rgb(255, 255, 255);"> <wbr></wbr></span></p><ul style="margin: 0px; padding: 0px; border: 0px; list-style: none;"><li style="margin: 0px 0px 0px 30px; padding: 0px; border: 0px; list-style: disc;"><span style="word-wrap: normal; word-break: normal; text-indent: 2em; background-color: rgb(255, 255, 255);">比较字符串大小:</span></li></ul><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal;"><span style="background-color: rgb(255, 255, 255);"> <wbr></wbr></span></p><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal;"><span style="background-color: rgb(255, 255, 255);">使用compare:<span style="word-wrap: normal; word-break: normal; text-indent: 2em;">升序返回</span><span style="word-wrap: normal; word-break: normal; text-indent: 2em;">-1</span><span style="word-wrap: normal; word-break: normal; text-indent: 2em;">，相等返回</span><span style="word-wrap: normal; word-break: normal; text-indent: 2em;">0</span><span style="word-wrap: normal; word-break: normal; text-indent: 2em;">，降序返回</span><span style="word-wrap: normal; word-break: normal; text-indent: 2em;">1</span></span></p><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal;"><span style="background-color: rgb(255, 255, 255);">如下：</span></p><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal;"><span style="background-color: rgb(255, 255, 255);"> <wbr></wbr></span></p><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal;"><span style="background-color: rgb(255, 255, 255);"><span style="word-wrap: normal; word-break: normal;">NSString</span> *k1 = <span style="word-wrap: normal; word-break: normal;">@"ABC"</span>;</span></p><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal;"><span style="background-color: rgb(255, 255, 255);"><span style="word-wrap: normal; word-break: normal;">NSString</span> *k2 = <span style="word-wrap: normal; word-break: normal;">@"ABc"</span>;</span></p><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal;"><span style="background-color: rgb(255, 255, 255);"><span style="word-wrap: normal; word-break: normal;">NSComparisonResult</span> r1 = [k1 <span style="word-wrap: normal; word-break: normal;">compare</span>:k2];</span></p><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal;"><span style="background-color: rgb(255, 255, 255);"><span style="word-wrap: normal; word-break: normal;">NSLog</span><span style="word-wrap: normal; word-break: normal;">(</span>@"r1 = %d"<span style="word-wrap: normal; word-break: normal;">,r1);</span></span></p><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal;"><span style="word-wrap: normal; word-break: normal; background-color: rgb(255, 255, 255);">结果输出为r1 = -1</span></p><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal;"><span style="background-color: rgb(255, 255, 255);"> <wbr></wbr></span></p><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal;"><span style="word-wrap: normal; word-break: normal; background-color: rgb(255, 255, 255);">转化字符串大小写:</span></p><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal;"><span style="background-color: rgb(255, 255, 255);"> <wbr></wbr></span></p><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal;"><span style="background-color: rgb(255, 255, 255);">lowercaseString: <wbr> <wbr> <wbr><span style="word-wrap: normal; word-break: normal; text-indent: 2em;">//</span><span style="word-wrap: normal; word-break: normal; text-indent: 2em;">转化成小写</span></wbr></wbr></wbr></span></p><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal;"><span style="background-color: rgb(255, 255, 255);"> <wbr></wbr></span></p><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal;"><span style="background-color: rgb(255, 255, 255);">uppercaseString: <wbr> <wbr> <wbr><span style="word-wrap: normal; word-break: normal; text-indent: 2em;">//</span><span style="word-wrap: normal; word-break: normal; text-indent: 2em;">转化成大写</span></wbr></wbr></wbr></span></p><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal;"><span style="background-color: rgb(255, 255, 255);">如下：</span></p><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal;"><span style="background-color: rgb(255, 255, 255);"> <wbr></wbr></span></p><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal;"><span style="background-color: rgb(255, 255, 255);"><span style="word-wrap: normal; word-break: normal;">NSString</span> *k3 = [k1 <span style="word-wrap: normal; word-break: normal;">lowercaseString</span>]; <wbr> <wbr></wbr></wbr></span></p><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal;"><span style="background-color: rgb(255, 255, 255);"><span style="word-wrap: normal; word-break: normal;">NSString</span> *k4 = [d1 <span style="word-wrap: normal; word-break: normal;">uppercaseString</span>]; <wbr></wbr></span></p><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal;"><span style="background-color: rgb(255, 255, 255);"> <wbr></wbr></span></p><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal;"><span style="background-color: rgb(255, 255, 255);"><span style="word-wrap: normal; word-break: normal;">NSLog</span><span style="word-wrap: normal; word-break: normal;">(</span>@"k3 = %@,k4 = %@"<span style="word-wrap: normal; word-break: normal;">,k3,k4);</span></span></p><p style="margin-top: 0px; margin-bottom: 5px; padding-top: 0px; padding-bottom: 0px; border: 0px; list-style: none; word-wrap: normal; word-break: normal;"><span style="background-color: rgb(255, 255, 255);">结果输出为：<span style="word-wrap: normal; word-break: normal; text-indent: 2em;">k3 = abc,k4 = ABC</span></span></p></div><div><span style="background-color: rgb(255, 255, 255);"><span style="word-wrap: normal; word-break: normal; text-indent: 2em;">
</span></span></div></div>
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