1.创建方法
2.长度
3.比较大小
4.比较相等
5.提取字符
6.提取字符串
7.查找字符串范围
initWithCString: encoding:
initWithUTF8String:
将C字符串按照指定格式转化为OC字符串;
UTF8String
cStringUsingEncoding:
OC 字符串转 C 字符串;
initWithString:
initWithFormat
stringWithFormat
拼接字符串;
length
compare
比较大小,如果返回1(NSOrderedDescending),s1
> s2;返回0(NSOrderedSame),两字符串相等;返回-1(NSOrderedAscending),s1
< s2;
caseInsensitiveCompare:s2
忽略大小写
isEqualToString:
uppercaseString
lowercaseString
characterAtIndex:
substringFromIndex:
substringToIndex:
//提取指定范围的字符串
substringWithRange:NSMakeRange(location, length)
//查找指定字符串的范围
rangeOfString: