Java奇葩笔试题

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<span style="font-size:14px; line-height:28px">1、下面代码中,在if处填写什么代码,可以使得输出结果为:AB</span></h2>
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<pre style="padding:9.5px; font-family:Monaco,Menlo,Consolas,'Courier New',monospace; font-size:13px; color:rgb(51,51,51); margin-top:0px; margin-bottom:-1px; line-height:20px; word-break:break-all; word-wrap:break-word; background-color:white; border:none"><span class="kd" style="color:rgb(0,128,0); font-weight:bold">public</span> <span class="kd" style="color:rgb(0,128,0); font-weight:bold">static</span> <span class="kt" style="color:rgb(176,0,64)">void</span> <span class="nf" style="color:rgb(0,0,255)">main</span><span class="o" style="color:rgb(102,102,102)">(</span><span class="n">String</span><span class="o" style="color:rgb(102,102,102)">[]</span> <span class="n">args</span><span class="o" style="color:rgb(102,102,102)">)</span> <span class="o" style="color:rgb(102,102,102)">{</span>


        <span class="k" style="color:rgb(0,128,0); font-weight:bold">if</span> <span class="o" style="color:rgb(102,102,102)">(</span>          <span class="o" style="color:rgb(102,102,102)">){</span><span class="c1" style="color:rgb(64,128,128); font-style:italic">//填写条件</span>
            <span class="n">System</span><span class="o" style="color:rgb(102,102,102)">.</span><span class="na" style="color:rgb(125,144,41)">out</span><span class="o" style="color:rgb(102,102,102)">.</span><span class="na" style="color:rgb(125,144,41)">print</span><span class="o" style="color:rgb(102,102,102)">(</span><span class="s" style="color:rgb(186,33,33)">"A"</span><span class="o" style="color:rgb(102,102,102)">);</span>
        <span class="o" style="color:rgb(102,102,102)">}</span> <span class="k" style="color:rgb(0,128,0); font-weight:bold">else</span> <span class="o" style="color:rgb(102,102,102)">{</span>
            <span class="n">System</span><span class="o" style="color:rgb(102,102,102)">.</span><span class="na" style="color:rgb(125,144,41)">out</span><span class="o" style="color:rgb(102,102,102)">.</span><span class="na" style="color:rgb(125,144,41)">print</span><span class="o" style="color:rgb(102,102,102)">(</span><span class="s" style="color:rgb(186,33,33)">"B"</span><span class="o" style="color:rgb(102,102,102)">);</span>
        <span class="o" style="color:rgb(102,102,102)">}</span>
    <span class="o" style="color:rgb(102,102,102)">}</span>
<span class="o" style="color:rgb(102,102,102)">}</span>
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2、 运算符问题,下面代码分别输出什么?</p>
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<pre style="padding:9.5px; font-family:Monaco,Menlo,Consolas,'Courier New',monospace; font-size:13px; color:rgb(51,51,51); margin-top:0px; margin-bottom:-1px; line-height:20px; word-break:break-all; word-wrap:break-word; background-color:white; border:none"><span class="kn" style="color:rgb(0,128,0); font-weight:bold">package</span> <span class="n">test</span><span class="o" style="color:rgb(102,102,102)">;</span>
<span class="kd" style="color:rgb(0,128,0); font-weight:bold">public</span> <span class="kd" style="color:rgb(0,128,0); font-weight:bold">class</span> <span class="nc" style="color:rgb(0,0,255); font-weight:bold">Test</span> <span class="o" style="color:rgb(102,102,102)">{</span>
    <span class="kd" style="color:rgb(0,128,0); font-weight:bold">public</span> <span class="kd" style="color:rgb(0,128,0); font-weight:bold">static</span> <span class="kt" style="color:rgb(176,0,64)">void</span> <span class="nf" style="color:rgb(0,0,255)">main</span><span class="o" style="color:rgb(102,102,102)">(</span><span class="n">String</span><span class="o" style="color:rgb(102,102,102)">[]</span> <span class="n">args</span><span class="o" style="color:rgb(102,102,102)">)</span> <span class="o" style="color:rgb(102,102,102)">{</span>
        <span class="kt" style="color:rgb(176,0,64)">int</span> <span class="n">i1</span> <span class="o" style="color:rgb(102,102,102)">=</span> <span class="mi" style="color:rgb(102,102,102)">10</span><span class="o" style="color:rgb(102,102,102)">,</span> <span class="n">i2</span> <span class="o" style="color:rgb(102,102,102)">=</span> <span class="mi" style="color:rgb(102,102,102)">10</span><span class="o" style="color:rgb(102,102,102)">;</span>
        <span class="n">System</span><span class="o" style="color:rgb(102,102,102)">.</span><span class="na" style="color:rgb(125,144,41)">err</span><span class="o" style="color:rgb(102,102,102)">.</span><span class="na" style="color:rgb(125,144,41)">println</span><span class="o" style="color:rgb(102,102,102)">(</span><span class="s" style="color:rgb(186,33,33)">"i1 + i2 = "</span> <span class="o" style="color:rgb(102,102,102)">+</span> <span class="n">i1</span> <span class="o" style="color:rgb(102,102,102)">+</span> <span class="n">i2</span><span class="o" style="color:rgb(102,102,102)">);</span>
        <span class="n">System</span><span class="o" style="color:rgb(102,102,102)">.</span><span class="na" style="color:rgb(125,144,41)">err</span><span class="o" style="color:rgb(102,102,102)">.</span><span class="na" style="color:rgb(125,144,41)">println</span><span class="o" style="color:rgb(102,102,102)">(</span><span class="s" style="color:rgb(186,33,33)">"i1 - i2 = "</span> <span class="o" style="color:rgb(102,102,102)">+</span> <span class="n">i1</span> <span class="o" style="color:rgb(102,102,102)">-</span> <span class="n">i2</span><span class="o" style="color:rgb(102,102,102)">);</span>
        <span class="n">System</span><span class="o" style="color:rgb(102,102,102)">.</span><span class="na" style="color:rgb(125,144,41)">err</span><span class="o" style="color:rgb(102,102,102)">.</span><span class="na" style="color:rgb(125,144,41)">println</span><span class="o" style="color:rgb(102,102,102)">(</span><span class="s" style="color:rgb(186,33,33)">"i1 * i2 = "</span> <span class="o" style="color:rgb(102,102,102)">+</span> <span class="n">i1</span> <span class="o" style="color:rgb(102,102,102)">*</span> <span class="n">i2</span><span class="o" style="color:rgb(102,102,102)">);</span>
        <span class="n">System</span><span class="o" style="color:rgb(102,102,102)">.</span><span class="na" style="color:rgb(125,144,41)">err</span><span class="o" style="color:rgb(102,102,102)">.</span><span class="na" style="color:rgb(125,144,41)">println</span><span class="o" style="color:rgb(102,102,102)">(</span><span class="s" style="color:rgb(186,33,33)">"i1 / i2 = "</span> <span class="o" style="color:rgb(102,102,102)">+</span> <span class="n">i1</span> <span class="o" style="color:rgb(102,102,102)">/</span> <span class="n">i2</span><span class="o" style="color:rgb(102,102,102)">);</span>
    <span class="o" style="color:rgb(102,102,102)">}</span>
<span class="o" style="color:rgb(102,102,102)">}</span>
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<p style="margin-top:0px; margin-bottom:10px; word-wrap:break-word; word-break:break-all">
3、下面代码的结果是什么?还是抛出异常?</p>
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<pre style="padding:9.5px; font-family:Monaco,Menlo,Consolas,'Courier New',monospace; font-size:13px; color:rgb(51,51,51); margin-top:0px; margin-bottom:-1px; line-height:20px; word-break:break-all; word-wrap:break-word; background-color:white; border:none"><span class="kn" style="color:rgb(0,128,0); font-weight:bold">package</span> <span class="n">test</span><span class="o" style="color:rgb(102,102,102)">;</span>


<span class="kd" style="color:rgb(0,128,0); font-weight:bold">public</span> <span class="kd" style="color:rgb(0,128,0); font-weight:bold">class</span> <span class="nc" style="color:rgb(0,0,255); font-weight:bold">Test</span> <span class="o" style="color:rgb(102,102,102)">{</span>


    <span class="kd" style="color:rgb(0,128,0); font-weight:bold">public</span> <span class="kt" style="color:rgb(176,0,64)">void</span> <span class="nf" style="color:rgb(0,0,255)">myMethod</span><span class="o" style="color:rgb(102,102,102)">(</span><span class="n">String</span> <span class="n">str</span><span class="o" style="color:rgb(102,102,102)">)</span> <span class="o" style="color:rgb(102,102,102)">{</span>
        <span class="n">System</span><span class="o" style="color:rgb(102,102,102)">.</span><span class="na" style="color:rgb(125,144,41)">err</span><span class="o" style="color:rgb(102,102,102)">.</span><span class="na" style="color:rgb(125,144,41)">println</span><span class="o" style="color:rgb(102,102,102)">(</span><span class="s" style="color:rgb(186,33,33)">"string"</span><span class="o" style="color:rgb(102,102,102)">);</span>
    <span class="o" style="color:rgb(102,102,102)">}</span>


    <span class="kd" style="color:rgb(0,128,0); font-weight:bold">public</span> <span class="kt" style="color:rgb(176,0,64)">void</span> <span class="nf" style="color:rgb(0,0,255)">myMethod</span><span class="o" style="color:rgb(102,102,102)">(</span><span class="n">Object</span> <span class="n">obj</span><span class="o" style="color:rgb(102,102,102)">)</span> <span class="o" style="color:rgb(102,102,102)">{</span>
        <span class="n">System</span><span class="o" style="color:rgb(102,102,102)">.</span><span class="na" style="color:rgb(125,144,41)">err</span><span class="o" style="color:rgb(102,102,102)">.</span><span class="na" style="color:rgb(125,144,41)">println</span><span class="o" style="color:rgb(102,102,102)">(</span><span class="s" style="color:rgb(186,33,33)">"object"</span><span class="o" style="color:rgb(102,102,102)">);</span>
    <span class="o" style="color:rgb(102,102,102)">}</span>


    <span class="kd" style="color:rgb(0,128,0); font-weight:bold">public</span> <span class="kd" style="color:rgb(0,128,0); font-weight:bold">static</span> <span class="kt" style="color:rgb(176,0,64)">void</span> <span class="nf" style="color:rgb(0,0,255)">main</span><span class="o" style="color:rgb(102,102,102)">(</span><span class="n">String</span><span class="o" style="color:rgb(102,102,102)">[]</span> <span class="n">args</span><span class="o" style="color:rgb(102,102,102)">)</span> <span class="o" style="color:rgb(102,102,102)">{</span>
        <span class="n">Test</span> <span class="n">t</span> <span class="o" style="color:rgb(102,102,102)">=</span> <span class="k" style="color:rgb(0,128,0); font-weight:bold">new</span> <span class="n">Test</span><span class="o" style="color:rgb(102,102,102)">();</span>
        <span class="n">t</span><span class="o" style="color:rgb(102,102,102)">.</span><span class="na" style="color:rgb(125,144,41)">myMethod</span><span class="o" style="color:rgb(102,102,102)">(</span><span class="kc" style="color:rgb(0,128,0); font-weight:bold">null</span><span class="o" style="color:rgb(102,102,102)">);</span>
    <span class="o" style="color:rgb(102,102,102)">}</span>
<span class="o" style="color:rgb(102,102,102)">}</span>
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4、下面代码的输出结果是什么?</p>
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<pre style="padding:9.5px; font-family:Monaco,Menlo,Consolas,'Courier New',monospace; font-size:13px; color:rgb(51,51,51); margin-top:0px; margin-bottom:-1px; line-height:20px; word-break:break-all; word-wrap:break-word; background-color:white; border:none"><span class="kn" style="color:rgb(0,128,0); font-weight:bold">package</span> <span class="n">test</span><span class="o" style="color:rgb(102,102,102)">;</span>


<span class="kd" style="color:rgb(0,128,0); font-weight:bold">public</span> <span class="kd" style="color:rgb(0,128,0); font-weight:bold">class</span> <span class="nc" style="color:rgb(0,0,255); font-weight:bold">Test</span> <span class="o" style="color:rgb(102,102,102)">{</span>


    <span class="kd" style="color:rgb(0,128,0); font-weight:bold">public</span> <span class="kd" style="color:rgb(0,128,0); font-weight:bold">static</span> <span class="kt" style="color:rgb(176,0,64)">void</span> <span class="nf" style="color:rgb(0,0,255)">main</span><span class="o" style="color:rgb(102,102,102)">(</span><span class="n">String</span><span class="o" style="color:rgb(102,102,102)">[]</span> <span class="n">args</span><span class="o" style="color:rgb(102,102,102)">)</span> <span class="o" style="color:rgb(102,102,102)">{</span>
        <span class="kt" style="color:rgb(176,0,64)">double</span> <span class="n">val</span> <span class="o" style="color:rgb(102,102,102)">=</span> <span class="mf" style="color:rgb(102,102,102)">11.5</span><span class="o" style="color:rgb(102,102,102)">;</span>
        <span class="n">System</span><span class="o" style="color:rgb(102,102,102)">.</span><span class="na" style="color:rgb(125,144,41)">err</span><span class="o" style="color:rgb(102,102,102)">.</span><span class="na" style="color:rgb(125,144,41)">println</span><span class="o" style="color:rgb(102,102,102)">(</span><span class="n">Math</span><span class="o" style="color:rgb(102,102,102)">.</span><span class="na" style="color:rgb(125,144,41)">round</span><span class="o" style="color:rgb(102,102,102)">(</span><span class="n">val</span><span class="o" style="color:rgb(102,102,102)">));</span>
        <span class="n">System</span><span class="o" style="color:rgb(102,102,102)">.</span><span class="na" style="color:rgb(125,144,41)">err</span><span class="o" style="color:rgb(102,102,102)">.</span><span class="na" style="color:rgb(125,144,41)">println</span><span class="o" style="color:rgb(102,102,102)">(</span><span class="n">Math</span><span class="o" style="color:rgb(102,102,102)">.</span><span class="na" style="color:rgb(125,144,41)">floor</span><span class="o" style="color:rgb(102,102,102)">(</span><span class="n">val</span><span class="o" style="color:rgb(102,102,102)">));</span>
        <span class="n">System</span><span class="o" style="color:rgb(102,102,102)">.</span><span class="na" style="color:rgb(125,144,41)">err</span><span class="o" style="color:rgb(102,102,102)">.</span><span class="na" style="color:rgb(125,144,41)">println</span><span class="o" style="color:rgb(102,102,102)">(</span><span class="n">Math</span><span class="o" style="color:rgb(102,102,102)">.</span><span class="na" style="color:rgb(125,144,41)">ceil</span><span class="o" style="color:rgb(102,102,102)">(</span><span class="n">val</span><span class="o" style="color:rgb(102,102,102)">));</span>
    <span class="o" style="color:rgb(102,102,102)">}</span>
<span class="o" style="color:rgb(102,102,102)">}</span>
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<p style="margin-top:0px; margin-bottom:10px; word-wrap:break-word; word-break:break-all">
5、 下面代码的结果是什么?</p>
<table class="highlighttable " style="max-width:100%; background-color:transparent; border-collapse:collapse; border-spacing:0px; word-wrap:break-word; word-break:break-all; width:910px; overflow-x:auto; margin:0px 0px 10px; padding:0px; border:1px solid rgb(204,204,204); display:block; overflow-y:hidden">
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<pre style="padding:0px 8px 0px 0px; font-family:Monaco,Menlo,Consolas,'Courier New',monospace; font-size:13px; color:rgb(51,51,51); margin-top:0px; margin-bottom:0px; line-height:20px; word-break:break-all; word-wrap:break-word; border:none; width:30px"> 1
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<div class="highlight" style="margin:0px; padding:0px; font-family:微软雅黑,Arial,Helvetica,sans-serif; word-wrap:break-word; word-break:break-all">
<pre style="padding:9.5px; font-family:Monaco,Menlo,Consolas,'Courier New',monospace; font-size:13px; color:rgb(51,51,51); margin-top:0px; margin-bottom:-1px; line-height:20px; word-break:break-all; word-wrap:break-word; background-color:white; border:none"><span class="kn" style="color:rgb(0,128,0); font-weight:bold">package</span> <span class="n">test</span><span class="o" style="color:rgb(102,102,102)">;</span>


<span class="kd" style="color:rgb(0,128,0); font-weight:bold">public</span> <span class="kd" style="color:rgb(0,128,0); font-weight:bold">class</span> <span class="nc" style="color:rgb(0,0,255); font-weight:bold">Test</span> <span class="kd" style="color:rgb(0,128,0); font-weight:bold">extends</span> <span class="n">Base</span> <span class="o" style="color:rgb(102,102,102)">{</span>


    <span class="kd" style="color:rgb(0,128,0); font-weight:bold">public</span> <span class="kd" style="color:rgb(0,128,0); font-weight:bold">static</span> <span class="kt" style="color:rgb(176,0,64)">void</span> <span class="nf" style="color:rgb(0,0,255)">main</span><span class="o" style="color:rgb(102,102,102)">(</span><span class="n">String</span><span class="o" style="color:rgb(102,102,102)">[]</span> <span class="n">args</span><span class="o" style="color:rgb(102,102,102)">)</span> <span class="o" style="color:rgb(102,102,102)">{</span>
        <span class="n">Base</span> <span class="n">b</span> <span class="o" style="color:rgb(102,102,102)">=</span> <span class="k" style="color:rgb(0,128,0); font-weight:bold">new</span> <span class="n">Test</span><span class="o" style="color:rgb(102,102,102)">();</span>
        <span class="n">b</span><span class="o" style="color:rgb(102,102,102)">.</span><span class="na" style="color:rgb(125,144,41)">method</span><span class="o" style="color:rgb(102,102,102)">();</span>


        <span class="n">Test</span> <span class="n">t</span> <span class="o" style="color:rgb(102,102,102)">=</span> <span class="k" style="color:rgb(0,128,0); font-weight:bold">new</span> <span class="n">Test</span><span class="o" style="color:rgb(102,102,102)">();</span>
        <span class="n">t</span><span class="o" style="color:rgb(102,102,102)">.</span><span class="na" style="color:rgb(125,144,41)">method</span><span class="o" style="color:rgb(102,102,102)">();</span>
    <span class="o" style="color:rgb(102,102,102)">}</span>


    <span class="nd" style="color:rgb(170,34,255)">@Override</span>
    <span class="kd" style="color:rgb(0,128,0); font-weight:bold">public</span> <span class="kt" style="color:rgb(176,0,64)">void</span> <span class="nf" style="color:rgb(0,0,255)">method</span><span class="o" style="color:rgb(102,102,102)">()</span> <span class="o" style="color:rgb(102,102,102)">{</span>
        <span class="n">System</span><span class="o" style="color:rgb(102,102,102)">.</span><span class="na" style="color:rgb(125,144,41)">err</span><span class="o" style="color:rgb(102,102,102)">.</span><span class="na" style="color:rgb(125,144,41)">println</span><span class="o" style="color:rgb(102,102,102)">(</span><span class="s" style="color:rgb(186,33,33)">"test"</span><span class="o" style="color:rgb(102,102,102)">);</span>
    <span class="o" style="color:rgb(102,102,102)">}</span>


<span class="o" style="color:rgb(102,102,102)">}</span>


<span class="kd" style="color:rgb(0,128,0); font-weight:bold">class</span> <span class="nc" style="color:rgb(0,0,255); font-weight:bold">Base</span> <span class="o" style="color:rgb(102,102,102)">{</span>
    <span class="kd" style="color:rgb(0,128,0); font-weight:bold">public</span> <span class="kt" style="color:rgb(176,0,64)">void</span> <span class="nf" style="color:rgb(0,0,255)">method</span><span class="o" style="color:rgb(102,102,102)">()</span> <span class="kd" style="color:rgb(0,128,0); font-weight:bold">throws</span> <span class="n">InterruptedException</span> <span class="o" style="color:rgb(102,102,102)">{</span>
        <span class="n">System</span><span class="o" style="color:rgb(102,102,102)">.</span><span class="na" style="color:rgb(125,144,41)">err</span><span class="o" style="color:rgb(102,102,102)">.</span><span class="na" style="color:rgb(125,144,41)">println</span><span class="o" style="color:rgb(102,102,102)">(</span><span class="s" style="color:rgb(186,33,33)">"base"</span><span class="o" style="color:rgb(102,102,102)">);</span>
    <span class="o" style="color:rgb(102,102,102)">}</span>
<span class="o" style="color:rgb(102,102,102)">}</span>
</pre>
</div>
</td>
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<p style="margin-top:0px; margin-bottom:10px; word-wrap:break-word; word-break:break-all">
6、以下代码的结果是什么?</p>
<table class="highlighttable " style="max-width:100%; background-color:transparent; border-collapse:collapse; border-spacing:0px; word-wrap:break-word; word-break:break-all; width:910px; overflow-x:auto; margin:0px 0px 10px; padding:0px; border:1px solid rgb(204,204,204); display:block; overflow-y:hidden">
<tbody>
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<pre style="padding:0px 8px 0px 0px; font-family:Monaco,Menlo,Consolas,'Courier New',monospace; font-size:13px; color:rgb(51,51,51); margin-top:0px; margin-bottom:0px; line-height:20px; word-break:break-all; word-wrap:break-word; border:none; width:30px"> 1
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<td class="code" style="word-wrap:break-word; word-break:break-all">
<div class="highlight" style="margin:0px; padding:0px; font-family:微软雅黑,Arial,Helvetica,sans-serif; word-wrap:break-word; word-break:break-all">
<pre style="padding:9.5px; font-family:Monaco,Menlo,Consolas,'Courier New',monospace; font-size:13px; color:rgb(51,51,51); margin-top:0px; margin-bottom:-1px; line-height:20px; word-break:break-all; word-wrap:break-word; background-color:white; border:none"><span class="kn" style="color:rgb(0,128,0); font-weight:bold">package</span> <span class="n">test</span><span class="o" style="color:rgb(102,102,102)">;</span>


<span class="kd" style="color:rgb(0,128,0); font-weight:bold">public</span> <span class="kd" style="color:rgb(0,128,0); font-weight:bold">class</span> <span class="nc" style="color:rgb(0,0,255); font-weight:bold">Test</span> <span class="kd" style="color:rgb(0,128,0); font-weight:bold">extends</span> <span class="n">Base</span> <span class="o" style="color:rgb(102,102,102)">{</span>


    <span class="kd" style="color:rgb(0,128,0); font-weight:bold">public</span> <span class="kd" style="color:rgb(0,128,0); font-weight:bold">static</span> <span class="kt" style="color:rgb(176,0,64)">void</span> <span class="nf" style="color:rgb(0,0,255)">main</span><span class="o" style="color:rgb(102,102,102)">(</span><span class="n">String</span><span class="o" style="color:rgb(102,102,102)">[]</span> <span class="n">args</span><span class="o" style="color:rgb(102,102,102)">)</span> <span class="o" style="color:rgb(102,102,102)">{</span>
        <span class="k" style="color:rgb(0,128,0); font-weight:bold">new</span> <span class="nf" style="color:rgb(0,0,255)">Test</span><span class="o" style="color:rgb(102,102,102)">().</span><span class="na" style="color:rgb(125,144,41)">method</span><span class="o" style="color:rgb(102,102,102)">();</span>
    <span class="o" style="color:rgb(102,102,102)">}</span>


    <span class="kd" style="color:rgb(0,128,0); font-weight:bold">public</span> <span class="kt" style="color:rgb(176,0,64)">void</span> <span class="nf" style="color:rgb(0,0,255)">method</span><span class="o" style="color:rgb(102,102,102)">()</span> <span class="o" style="color:rgb(102,102,102)">{</span>
        <span class="n">System</span><span class="o" style="color:rgb(102,102,102)">.</span><span class="na" style="color:rgb(125,144,41)">err</span><span class="o" style="color:rgb(102,102,102)">.</span><span class="na" style="color:rgb(125,144,41)">println</span><span class="o" style="color:rgb(102,102,102)">(</span><span class="k" style="color:rgb(0,128,0); font-weight:bold">this</span><span class="o" style="color:rgb(102,102,102)">.</span><span class="na" style="color:rgb(125,144,41)">getClass</span><span class="o" style="color:rgb(102,102,102)">().</span><span class="na" style="color:rgb(125,144,41)">getName</span><span class="o" style="color:rgb(102,102,102)">());</span>
        <span class="n">System</span><span class="o" style="color:rgb(102,102,102)">.</span><span class="na" style="color:rgb(125,144,41)">err</span><span class="o" style="color:rgb(102,102,102)">.</span><span class="na" style="color:rgb(125,144,41)">println</span><span class="o" style="color:rgb(102,102,102)">(</span><span class="kd" style="color:rgb(0,128,0); font-weight:bold">super</span><span class="o" style="color:rgb(102,102,102)">.</span><span class="na" style="color:rgb(125,144,41)">getClass</span><span class="o" style="color:rgb(102,102,102)">().</span><span class="na" style="color:rgb(125,144,41)">getName</span><span class="o" style="color:rgb(102,102,102)">());</span>
        <span class="n">System</span><span class="o" style="color:rgb(102,102,102)">.</span><span class="na" style="color:rgb(125,144,41)">err</span><span class="o" style="color:rgb(102,102,102)">.</span><span class="na" style="color:rgb(125,144,41)">println</span><span class="o" style="color:rgb(102,102,102)">(</span><span class="k" style="color:rgb(0,128,0); font-weight:bold">this</span><span class="o" style="color:rgb(102,102,102)">.</span><span class="na" style="color:rgb(125,144,41)">getClass</span><span class="o" style="color:rgb(102,102,102)">().</span><span class="na" style="color:rgb(125,144,41)">getSuperclass</span><span class="o" style="color:rgb(102,102,102)">().</span><span class="na" style="color:rgb(125,144,41)">getName</span><span class="o" style="color:rgb(102,102,102)">());</span>
        <span class="n">System</span><span class="o" style="color:rgb(102,102,102)">.</span><span class="na" style="color:rgb(125,144,41)">err</span><span class="o" style="color:rgb(102,102,102)">.</span><span class="na" style="color:rgb(125,144,41)">println</span><span class="o" style="color:rgb(102,102,102)">(</span><span class="kd" style="color:rgb(0,128,0); font-weight:bold">super</span><span class="o" style="color:rgb(102,102,102)">.</span><span class="na" style="color:rgb(125,144,41)">getClass</span><span class="o" style="color:rgb(102,102,102)">().</span><span class="na" style="color:rgb(125,144,41)">getSuperclass</span><span class="o" style="color:rgb(102,102,102)">().</span><span class="na" style="color:rgb(125,144,41)">getName</span><span class="o" style="color:rgb(102,102,102)">());</span>
    <span class="o" style="color:rgb(102,102,102)">}</span>


<span class="o" style="color:rgb(102,102,102)">}</span>


<span class="kd" style="color:rgb(0,128,0); font-weight:bold">class</span> <span class="nc" style="color:rgb(0,0,255); font-weight:bold">Base</span> <span class="o" style="color:rgb(102,102,102)">{</span>
<span class="o" style="color:rgb(102,102,102)">}</span>
</pre>
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</td>
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</table>
<p style="margin-top:0px; margin-bottom:10px; word-wrap:break-word; word-break:break-all">
7、true or false?</p>
<table class="highlighttable " style="max-width:100%; background-color:transparent; border-collapse:collapse; border-spacing:0px; word-wrap:break-word; word-break:break-all; width:910px; overflow-x:auto; margin:0px 0px 10px; padding:0px; border:1px solid rgb(204,204,204); display:block; overflow-y:hidden">
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<div class="linenodiv" style="margin:0px; padding:0px; font-family:微软雅黑,Arial,Helvetica,sans-serif; word-wrap:break-word; word-break:break-all">
<pre style="padding:0px 8px 0px 0px; font-family:Monaco,Menlo,Consolas,'Courier New',monospace; font-size:13px; color:rgb(51,51,51); margin-top:0px; margin-bottom:0px; line-height:20px; word-break:break-all; word-wrap:break-word; border:none; width:30px"> 1
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<div class="highlight" style="margin:0px; padding:0px; font-family:微软雅黑,Arial,Helvetica,sans-serif; word-wrap:break-word; word-break:break-all">
<pre style="padding:9.5px; font-family:Monaco,Menlo,Consolas,'Courier New',monospace; font-size:13px; color:rgb(51,51,51); margin-top:0px; margin-bottom:-1px; line-height:20px; word-break:break-all; word-wrap:break-word; background-color:white; border:none"><span class="kn" style="color:rgb(0,128,0); font-weight:bold">package</span> <span class="n">test</span><span class="o" style="color:rgb(102,102,102)">;</span>


<span class="kd" style="color:rgb(0,128,0); font-weight:bold">public</span> <span class="kd" style="color:rgb(0,128,0); font-weight:bold">class</span> <span class="nc" style="color:rgb(0,0,255); font-weight:bold">Test</span> <span class="o" style="color:rgb(102,102,102)">{</span>


    <span class="kd" style="color:rgb(0,128,0); font-weight:bold">public</span> <span class="kd" style="color:rgb(0,128,0); font-weight:bold">static</span> <span class="kt" style="color:rgb(176,0,64)">void</span> <span class="nf" style="color:rgb(0,0,255)">main</span><span class="o" style="color:rgb(102,102,102)">(</span><span class="n">String</span><span class="o" style="color:rgb(102,102,102)">[]</span> <span class="n">args</span><span class="o" style="color:rgb(102,102,102)">)</span> <span class="o" style="color:rgb(102,102,102)">{</span>
        <span class="n">String</span> <span class="n">str1</span> <span class="o" style="color:rgb(102,102,102)">=</span> <span class="k" style="color:rgb(0,128,0); font-weight:bold">new</span> <span class="n">String</span><span class="o" style="color:rgb(102,102,102)">(</span><span class="s" style="color:rgb(186,33,33)">"abc"</span><span class="o" style="color:rgb(102,102,102)">);</span>
        <span class="n">String</span> <span class="n">str2</span> <span class="o" style="color:rgb(102,102,102)">=</span> <span class="k" style="color:rgb(0,128,0); font-weight:bold">new</span> <span class="n">String</span><span class="o" style="color:rgb(102,102,102)">(</span><span class="s" style="color:rgb(186,33,33)">"abc"</span><span class="o" style="color:rgb(102,102,102)">);</span>
        <span class="n">System</span><span class="o" style="color:rgb(102,102,102)">.</span><span class="na" style="color:rgb(125,144,41)">err</span><span class="o" style="color:rgb(102,102,102)">.</span><span class="na" style="color:rgb(125,144,41)">println</span><span class="o" style="color:rgb(102,102,102)">(</span><span class="n">str1</span><span class="o" style="color:rgb(102,102,102)">.</span><span class="na" style="color:rgb(125,144,41)">equals</span><span class="o" style="color:rgb(102,102,102)">(</span><span class="n">str2</span><span class="o" style="color:rgb(102,102,102)">));</span>


        <span class="n">StringBuffer</span> <span class="n">sb1</span> <span class="o" style="color:rgb(102,102,102)">=</span> <span class="k" style="color:rgb(0,128,0); font-weight:bold">new</span> <span class="n">StringBuffer</span><span class="o" style="color:rgb(102,102,102)">(</span><span class="s" style="color:rgb(186,33,33)">"abc"</span><span class="o" style="color:rgb(102,102,102)">);</span>
        <span class="n">StringBuffer</span> <span class="n">sb2</span> <span class="o" style="color:rgb(102,102,102)">=</span> <span class="k" style="color:rgb(0,128,0); font-weight:bold">new</span> <span class="n">StringBuffer</span><span class="o" style="color:rgb(102,102,102)">(</span><span class="s" style="color:rgb(186,33,33)">"abc"</span><span class="o" style="color:rgb(102,102,102)">);</span>
        <span class="n">System</span><span class="o" style="color:rgb(102,102,102)">.</span><span class="na" style="color:rgb(125,144,41)">err</span><span class="o" style="color:rgb(102,102,102)">.</span><span class="na" style="color:rgb(125,144,41)">println</span><span class="o" style="color:rgb(102,102,102)">(</span><span class="n">sb1</span><span class="o" style="color:rgb(102,102,102)">.</span><span class="na" style="color:rgb(125,144,41)">equals</span><span class="o" style="color:rgb(102,102,102)">(</span><span class="n">sb2</span><span class="o" style="color:rgb(102,102,102)">));</span>
    <span class="o" style="color:rgb(102,102,102)">}</span>
<span class="o" style="color:rgb(102,102,102)">}</span>
</pre>
</div>
</td>
</tr>
</tbody>
</table>
<p style="margin-top:0px; margin-bottom:10px; word-wrap:break-word; word-break:break-all">
8、输出的结果是什么?</p>
<table class="highlighttable " style="max-width:100%; background-color:transparent; border-collapse:collapse; border-spacing:0px; word-wrap:break-word; word-break:break-all; width:910px; overflow-x:auto; margin:0px 0px 10px; padding:0px; border:1px solid rgb(204,204,204); display:block; overflow-y:hidden">
<tbody>
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<td class="linenos" style="word-wrap:break-word; word-break:break-all; width:25px; text-align:right; border-right-width:1px; border-right-style:solid; border-right-color:rgb(204,204,204); background-color:rgb(245,245,245)">
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<pre style="padding:0px 8px 0px 0px; font-family:Monaco,Menlo,Consolas,'Courier New',monospace; font-size:13px; color:rgb(51,51,51); margin-top:0px; margin-bottom:0px; line-height:20px; word-break:break-all; word-wrap:break-word; border:none; width:30px"> 1
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</td>
<td class="code" style="word-wrap:break-word; word-break:break-all">
<div class="highlight" style="margin:0px; padding:0px; font-family:微软雅黑,Arial,Helvetica,sans-serif; word-wrap:break-word; word-break:break-all">
<pre style="padding:9.5px; font-family:Monaco,Menlo,Consolas,'Courier New',monospace; font-size:13px; color:rgb(51,51,51); margin-top:0px; margin-bottom:-1px; line-height:20px; word-break:break-all; word-wrap:break-word; background-color:white; border:none"><span class="kn" style="color:rgb(0,128,0); font-weight:bold">package</span> <span class="n">test</span><span class="o" style="color:rgb(102,102,102)">;</span>


<span class="kd" style="color:rgb(0,128,0); font-weight:bold">public</span> <span class="kd" style="color:rgb(0,128,0); font-weight:bold">class</span> <span class="nc" style="color:rgb(0,0,255); font-weight:bold">Test</span> <span class="o" style="color:rgb(102,102,102)">{</span>


    <span class="kd" style="color:rgb(0,128,0); font-weight:bold">public</span> <span class="kd" style="color:rgb(0,128,0); font-weight:bold">static</span> <span class="kt" style="color:rgb(176,0,64)">void</span> <span class="nf" style="color:rgb(0,0,255)">main</span><span class="o" style="color:rgb(102,102,102)">(</span><span class="n">String</span><span class="o" style="color:rgb(102,102,102)">[]</span> <span class="n">args</span><span class="o" style="color:rgb(102,102,102)">)</span> <span class="o" style="color:rgb(102,102,102)">{</span>
        <span class="n">System</span><span class="o" style="color:rgb(102,102,102)">.</span><span class="na" style="color:rgb(125,144,41)">err</span><span class="o" style="color:rgb(102,102,102)">.</span><span class="na" style="color:rgb(125,144,41)">println</span><span class="o" style="color:rgb(102,102,102)">(</span><span class="k" style="color:rgb(0,128,0); font-weight:bold">new</span> <span class="n">Test</span><span class="o" style="color:rgb(102,102,102)">().</span><span class="na" style="color:rgb(125,144,41)">method1</span><span class="o" style="color:rgb(102,102,102)">());</span>
        <span class="n">System</span><span class="o" style="color:rgb(102,102,102)">.</span><span class="na" style="color:rgb(125,144,41)">err</span><span class="o" style="color:rgb(102,102,102)">.</span><span class="na" style="color:rgb(125,144,41)">println</span><span class="o" style="color:rgb(102,102,102)">(</span><span class="k" style="color:rgb(0,128,0); font-weight:bold">new</span> <span class="n">Test</span><span class="o" style="color:rgb(102,102,102)">().</span><span class="na" style="color:rgb(125,144,41)">method2</span><span class="o" style="color:rgb(102,102,102)">());</span>
    <span class="o" style="color:rgb(102,102,102)">}</span>


    <span class="kd" style="color:rgb(0,128,0); font-weight:bold">public</span> <span class="kt" style="color:rgb(176,0,64)">int</span> <span class="nf" style="color:rgb(0,0,255)">method1</span><span class="o" style="color:rgb(102,102,102)">()</span> <span class="o" style="color:rgb(102,102,102)">{</span>
        <span class="kt" style="color:rgb(176,0,64)">int</span> <span class="n">x</span> <span class="o" style="color:rgb(102,102,102)">=</span> <span class="mi" style="color:rgb(102,102,102)">1</span><span class="o" style="color:rgb(102,102,102)">;</span>
        <span class="k" style="color:rgb(0,128,0); font-weight:bold">try</span> <span class="o" style="color:rgb(102,102,102)">{</span>
            <span class="k" style="color:rgb(0,128,0); font-weight:bold">return</span> <span class="n">x</span><span class="o" style="color:rgb(102,102,102)">;</span>
        <span class="o" style="color:rgb(102,102,102)">}</span> <span class="k" style="color:rgb(0,128,0); font-weight:bold">finally</span> <span class="o" style="color:rgb(102,102,102)">{</span>
            <span class="o" style="color:rgb(102,102,102)">++</span><span class="n">x</span><span class="o" style="color:rgb(102,102,102)">;</span>
        <span class="o" style="color:rgb(102,102,102)">}</span>
    <span class="o" style="color:rgb(102,102,102)">}</span>


    <span class="kd" style="color:rgb(0,128,0); font-weight:bold">public</span> <span class="kt" style="color:rgb(176,0,64)">int</span> <span class="nf" style="color:rgb(0,0,255)">method2</span><span class="o" style="color:rgb(102,102,102)">()</span> <span class="o" style="color:rgb(102,102,102)">{</span>
        <span class="kt" style="color:rgb(176,0,64)">int</span> <span class="n">x</span> <span class="o" style="color:rgb(102,102,102)">=</span> <span class="mi" style="color:rgb(102,102,102)">1</span><span class="o" style="color:rgb(102,102,102)">;</span>
        <span class="k" style="color:rgb(0,128,0); font-weight:bold">try</span> <span class="o" style="color:rgb(102,102,102)">{</span>
            <span class="k" style="color:rgb(0,128,0); font-weight:bold">return</span> <span class="n">x</span><span class="o" style="color:rgb(102,102,102)">;</span>
        <span class="o" style="color:rgb(102,102,102)">}</span> <span class="k" style="color:rgb(0,128,0); font-weight:bold">finally</span> <span class="o" style="color:rgb(102,102,102)">{</span>
            <span class="k" style="color:rgb(0,128,0); font-weight:bold">return</span> <span class="o" style="color:rgb(102,102,102)">++</span><span class="n">x</span><span class="o" style="color:rgb(102,102,102)">;</span>
        <span class="o" style="color:rgb(102,102,102)">}</span>
    <span class="o" style="color:rgb(102,102,102)">}</span>
<span class="o" style="color:rgb(102,102,102)">}</span>
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9、true or false?</p>
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<pre style="padding:9.5px; font-family:Monaco,Menlo,Consolas,'Courier New',monospace; font-size:13px; color:rgb(51,51,51); margin-top:0px; margin-bottom:-1px; line-height:20px; word-break:break-all; word-wrap:break-word; background-color:white; border:none"><span class="kn" style="color:rgb(0,128,0); font-weight:bold">package</span> <span class="n">test</span><span class="o" style="color:rgb(102,102,102)">;</span>


<span class="kd" style="color:rgb(0,128,0); font-weight:bold">public</span> <span class="kd" style="color:rgb(0,128,0); font-weight:bold">class</span> <span class="nc" style="color:rgb(0,0,255); font-weight:bold">Test</span> <span class="o" style="color:rgb(102,102,102)">{</span>


    <span class="kd" style="color:rgb(0,128,0); font-weight:bold">public</span> <span class="kd" style="color:rgb(0,128,0); font-weight:bold">static</span> <span class="kt" style="color:rgb(176,0,64)">void</span> <span class="nf" style="color:rgb(0,0,255)">main</span><span class="o" style="color:rgb(102,102,102)">(</span><span class="n">String</span><span class="o" style="color:rgb(102,102,102)">[]</span> <span class="n">args</span><span class="o" style="color:rgb(102,102,102)">)</span> <span class="o" style="color:rgb(102,102,102)">{</span>
        <span class="n">System</span><span class="o" style="color:rgb(102,102,102)">.</span><span class="na" style="color:rgb(125,144,41)">err</span><span class="o" style="color:rgb(102,102,102)">.</span><span class="na" style="color:rgb(125,144,41)">println</span><span class="o" style="color:rgb(102,102,102)">(</span><span class="mi" style="color:rgb(102,102,102)">12</span> <span class="o" style="color:rgb(102,102,102)">-</span> <span class="mf" style="color:rgb(102,102,102)">11.9</span> <span class="o" style="color:rgb(102,102,102)">==</span> <span class="mf" style="color:rgb(102,102,102)">0.1</span><span class="o" style="color:rgb(102,102,102)">);</span>
    <span class="o" style="color:rgb(102,102,102)">}</span>
<span class="o" style="color:rgb(102,102,102)">}</span>
</pre>
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10、以下代码输出是什么?</p>
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<pre style="padding:9.5px; font-family:Monaco,Menlo,Consolas,'Courier New',monospace; font-size:13px; color:rgb(51,51,51); margin-top:0px; margin-bottom:-1px; line-height:20px; word-break:break-all; word-wrap:break-word; background-color:white; border:none"><span class="kn" style="color:rgb(0,128,0); font-weight:bold">package</span> <span class="n">test</span><span class="o" style="color:rgb(102,102,102)">;</span>


<span class="kn" style="color:rgb(0,128,0); font-weight:bold">import</span> <span class="nn" style="color:rgb(0,0,255); font-weight:bold">java.math.BigInteger</span><span class="o" style="color:rgb(102,102,102)">;</span>


<span class="kd" style="color:rgb(0,128,0); font-weight:bold">public</span> <span class="kd" style="color:rgb(0,128,0); font-weight:bold">class</span> <span class="nc" style="color:rgb(0,0,255); font-weight:bold">Test</span> <span class="o" style="color:rgb(102,102,102)">{</span>








    <span class="kd" style="color:rgb(0,128,0); font-weight:bold">public</span> <span class="kd" style="color:rgb(0,128,0); font-weight:bold">static</span> <span class="kt" style="color:rgb(176,0,64)">void</span> <span class="nf" style="color:rgb(0,0,255)">main</span><span class="o" style="color:rgb(102,102,102)">(</span><span class="n">String</span><span class="o" style="color:rgb(102,102,102)">[]</span> <span class="n">args</span><span class="o" style="color:rgb(102,102,102)">)</span> <span class="o" style="color:rgb(102,102,102)">{</span>
        <span class="n">BigInteger</span> <span class="n">one</span> <span class="o" style="color:rgb(102,102,102)">=</span> <span class="k" style="color:rgb(0,128,0); font-weight:bold">new</span> <span class="n">BigInteger</span><span class="o" style="color:rgb(102,102,102)">(</span><span class="s" style="color:rgb(186,33,33)">"1"</span><span class="o" style="color:rgb(102,102,102)">);</span>
        <span class="n">BigInteger</span> <span class="n">two</span> <span class="o" style="color:rgb(102,102,102)">=</span> <span class="k" style="color:rgb(0,128,0); font-weight:bold">new</span> <span class="n">BigInteger</span><span class="o" style="color:rgb(102,102,102)">(</span><span class="s" style="color:rgb(186,33,33)">"2"</span><span class="o" style="color:rgb(102,102,102)">);</span>
        <span class="n">BigInteger</span> <span class="n">three</span> <span class="o" style="color:rgb(102,102,102)">=</span> <span class="k" style="color:rgb(0,128,0); font-weight:bold">new</span> <span class="n">BigInteger</span><span class="o" style="color:rgb(102,102,102)">(</span><span class="s" style="color:rgb(186,33,33)">"3"</span><span class="o" style="color:rgb(102,102,102)">);</span>
        <span class="n">BigInteger</span> <span class="n">sum</span> <span class="o" style="color:rgb(102,102,102)">=</span> <span class="k" style="color:rgb(0,128,0); font-weight:bold">new</span> <span class="n">BigInteger</span><span class="o" style="color:rgb(102,102,102)">(</span><span class="s" style="color:rgb(186,33,33)">"0"</span><span class="o" style="color:rgb(102,102,102)">);</span>
        <span class="n">sum</span><span class="o" style="color:rgb(102,102,102)">.</span><span class="na" style="color:rgb(125,144,41)">add</span><span class="o" style="color:rgb(102,102,102)">(</span><span class="n">one</span><span class="o" style="color:rgb(102,102,102)">);</span>
        <span class="n">sum</span><span class="o" style="color:rgb(102,102,102)">.</span><span class="na" style="color:rgb(125,144,41)">add</span><span class="o" style="color:rgb(102,102,102)">(</span><span class="n">two</span><span class="o" style="color:rgb(102,102,102)">);</span>
        <span class="n">sum</span><span class="o" style="color:rgb(102,102,102)">.</span><span class="na" style="color:rgb(125,144,41)">add</span><span class="o" style="color:rgb(102,102,102)">(</span><span class="n">three</span><span class="o" style="color:rgb(102,102,102)">);</span>
        <span class="n">System</span><span class="o" style="color:rgb(102,102,102)">.</span><span class="na" style="color:rgb(125,144,41)">out</span><span class="o" style="color:rgb(102,102,102)">.</span><span class="na" style="color:rgb(125,144,41)">println</span><span class="o" style="color:rgb(102,102,102)">(</span><span class="n">sum</span><span class="o" style="color:rgb(102,102,102)">.</span><span class="na" style="color:rgb(125,144,41)">toString</span><span class="o" style="color:rgb(102,102,102)">());</span>
    <span class="o" style="color:rgb(102,102,102)">}</span>
<span class="o" style="color:rgb(102,102,102)">}</span>
</pre>
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<p style="margin-top:0px; margin-bottom:10px; word-wrap:break-word; word-break:break-all">
答案:</p>
<p style="margin-top:0px; margin-bottom:10px; word-wrap:break-word; word-break:break-all">
(1)、 System.out.printf("A") == null</p>
<p style="margin-top:0px; margin-bottom:10px; word-wrap:break-word; word-break:break-all">
(2)、</p>
<p style="margin-top:0px; margin-bottom:10px; word-wrap:break-word; word-break:break-all">
第一行结果i1 + i2 = 1010</p>
<p style="margin-top:0px; margin-bottom:10px; word-wrap:break-word; word-break:break-all">
第二行异常,字符串不能和数字做减法</p>
<p style="margin-top:0px; margin-bottom:10px; word-wrap:break-word; word-break:break-all">
第三行i1 * i2 = 100</p>
<p style="margin-top:0px; margin-bottom:10px; word-wrap:break-word; word-break:break-all">
第四行i1 / i2 = 1</p>
<p style="margin-top:0px; margin-bottom:10px; word-wrap:break-word; word-break:break-all">
(3)、尽可能的从子类找,因此是string</p>
<p style="margin-top:0px; margin-bottom:10px; word-wrap:break-word; word-break:break-all">
(4)、要注意返回类型long,double,double,答案是</p>
<p style="margin-top:0px; margin-bottom:10px; word-wrap:break-word; word-break:break-all">
12</p>
<p style="margin-top:0px; margin-bottom:10px; word-wrap:break-word; word-break:break-all">
11.0</p>
<p style="margin-top:0px; margin-bottom:10px; word-wrap:break-word; word-break:break-all">
12.0</p>
<p style="margin-top:0px; margin-bottom:10px; word-wrap:break-word; word-break:break-all">
(5)、 答:异常。因为子类重写父类方法时也要抛出异常。</p>
<p style="margin-top:0px; margin-bottom:10px; word-wrap:break-word; word-break:break-all">
(6)、</p>
<p style="margin-top:0px; margin-bottom:10px; word-wrap:break-word; word-break:break-all">
test.Test</p>
<p style="margin-top:0px; margin-bottom:10px; word-wrap:break-word; word-break:break-all">
test.Test</p>
<p style="margin-top:0px; margin-bottom:10px; word-wrap:break-word; word-break:break-all">
test.Base</p>
<p style="margin-top:0px; margin-bottom:10px; word-wrap:break-word; word-break:break-all">
test.Base</p>
<p style="margin-top:0px; margin-bottom:10px; word-wrap:break-word; word-break:break-all">
(7)、</p>
<p style="margin-top:0px; margin-bottom:10px; word-wrap:break-word; word-break:break-all">
true</p>
<p style="margin-top:0px; margin-bottom:10px; word-wrap:break-word; word-break:break-all">
false</p>
<p style="margin-top:0px; margin-bottom:10px; word-wrap:break-word; word-break:break-all">
(8)、</p>
<p style="margin-top:0px; margin-bottom:10px; word-wrap:break-word; word-break:break-all">
1</p>
<p style="margin-top:0px; margin-bottom:10px; word-wrap:break-word; word-break:break-all">
2</p>
<p style="margin-top:0px; margin-bottom:10px; word-wrap:break-word; word-break:break-all">
(9)、 false</p>
<p style="margin-top:0px; margin-bottom:10px; word-wrap:break-word; word-break:break-all">
(10)、0</p>
<p style="margin-top:0px; margin-bottom:10px; word-wrap:break-word; word-break:break-all">
转载自:http://my.eoe.cn/zhongcx/archive/24063.html</p>
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CH341A编程器是一款广泛应用的通用编程设备,尤其在电子工程和嵌入式系统开发领域中,它被用来烧录各种类型的微控制器、存储器和其他IC芯片。这款编程器的最新版本为1.3,它的一个显著特点是增加了对25Q256等32M芯片的支持。 25Q256是一种串行EEPROM(电可擦可编程只读存储器)芯片,通常用于存储程序代码、配置数据或其他非易失性信息。32M在这里指的是存储容量,即该芯片可以存储32兆位(Mbit)的数据,换算成字节数就是4MB。这种大容量的存储器在许多嵌入式系统中都有应用,例如汽车电子、工业控制、消费电子设备等。 CH341A编程器的1.3版更新,意味着它可以与更多的芯片型号兼容,特别是针对32M容量的芯片进行了优化,提高了编程效率和稳定性。26系列芯片通常指的是Microchip公司的25系列SPI(串行外围接口)EEPROM产品线,这些芯片广泛应用于各种需要小体积、低功耗和非易失性存储的应用场景。 全功能版的CH341A编程器不仅支持25Q256,还支持其他大容量芯片,这意味着它具有广泛的兼容性,能够满足不同项目的需求。这包括但不限于微控制器、EPROM、EEPROM、闪存、逻辑门电路等多种类型芯片的编程。 使用CH341A编程器进行编程操作时,首先需要将设备通过USB连接到计算机,然后安装相应的驱动程序和编程软件。在本例中,压缩包中的"CH341A_1.30"很可能是编程软件的安装程序。安装后,用户可以通过软件界面选择需要编程的芯片类型,加载待烧录的固件或数据,然后执行编程操作。编程过程中需要注意的是,确保正确设置芯片的电压、时钟频率等参数,以防止损坏芯片。 CH341A编程器1.3版是面向电子爱好者和专业工程师的一款实用工具,其强大的兼容性和易用性使其在众多编程器中脱颖而出。对于需要处理25Q256等32M芯片的项目,或者26系列芯片的编程工作,CH341A编程器是理想的选择。通过持续的软件更新和升级,它保持了与现代电子技术同步,确保用户能方便地对各种芯片进行编程和调试。
内存分区情况的分析是嵌入式系统开发中的一个重要环节,特别是在资源有限的MCU(微控制器)环境中。标提到的工具是一款专为分析Linux环境下的`gcc-map`文件设计的工具,这类文件在编译过程结束后生成,包含了程序在目标设备内存中的布局信息。这个工具可以帮助开发者理解程序在RAM、ROM以及FLASH等存储区域的占用情况,从而进行优化。 `gcc-map`文件通常包含以下关键信息: 1. **符号表**:列出所有定义的全局和静态变量、函数以及其他符号,包括它们的地址和大小。 2. **节区分配**:显示每个代码和数据节区在内存中的位置,比如.text(代码)、.data(已初始化数据)、.bss(未初始化数据)等。 3. **内存汇总**:总览所有节区的大小,有助于评估程序的整体内存需求。 4. **重定位信息**:显示了代码和数据如何在目标地址空间中定位。 该分析工具可能提供以下功能: 1. **可视化展示**:将内存分配以图形化方式呈现,便于直观理解。 2. **详细报告**:生成详细的分析报告,列出每个符号的大小和位置。 3. **比较功能**:对比不同编译版本或配置的`map`文件,查看内存使用的变化。 4. **统计分析**:计算各种内存区域的使用率,帮助识别潜在的优化点。 5. **自定义过滤**:允许用户根据需要筛选和关注特定的符号或节区。 虽然在MCU环境中,Keil IDE自带的工具可能更方便,因为它们通常针对特定的MCU型号进行了优化,提供更加细致的硬件相关分析。然而,对于通用的Linux系统或跨平台项目,这款基于`gcc-map`的分析工具提供了更广泛的适用性。 在实际使用过程中,开发者可以利用这款工具来: - **优化内存使用**:通过分析哪些函数或数据占用过多的内存,进行代码重构或调整链接器脚本以减小体积。 - **排查内存泄漏**:结合其他工具,比如动态内存检测工具,查找可能导致内存泄漏的部分。 - **性能调优**:了解代码执行时的内存分布,有助于提高运行效率。 - **满足资源限制**:在嵌入式系统中,确保程序能在有限的内存空间内运行。 总结来说,`gcc-amap`这样的工具对于深入理解程序的内存布局和资源消耗至关重要,它能帮助开发者做出更明智的决策,优化代码以适应不同的硬件环境。在处理`map`文件时,开发者不仅能获取到程序的内存占用情况,还能进一步挖掘出可能的优化空间,从而提升系统的整体性能和效率。
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