详细的操作符的属性

ゝ一纸荒年。 2022-12-27 14:20 130阅读 0赞

## 操作符的属性 ##

##### 复杂表达式的求值有三个影响因素。 #####

> 1.操作符的优先级  
> 2.操作符的结合性  
> 3.是否控制求值顺序。

两个相邻的操作符先执行那个？取决于他们的优先级。如果两者的优先级相同，取决于他们的结合性。

<table> 
 <thead> 
  <tr> 
   <th>操作符</th> 
   <th>描述</th> 
   <th>用法用例</th> 
   <th>结果类型</th> 
   <th>结合性</th> 
   <th>是否控制求值顺序</th> 
  </tr> 
 </thead> 
 <tbody> 
  <tr> 
   <td>（）</td> 
   <td>聚组</td> 
   <td>（表达式）</td> 
   <td>与表达式相同</td> 
   <td>N/A</td> 
   <td>否</td> 
  </tr> 
  <tr> 
   <td>()</td> 
   <td>函数调用</td> 
   <td>repx(repx,…,repx)</td> 
   <td>repx</td> 
   <td>L-R</td> 
   <td>否</td> 
  </tr> 
  <tr> 
   <td>[ ]</td> 
   <td>下标引用</td> 
   <td>repx[repx]</td> 
   <td>lexp</td> 
   <td>L-R</td> 
   <td>否</td> 
  </tr> 
  <tr> 
   <td>.</td> 
   <td>访问结构成员</td> 
   <td>lexp.member_name</td> 
   <td>lexp</td> 
   <td>L-R</td> 
   <td>否</td> 
  </tr> 
  <tr> 
   <td>-&gt;</td> 
   <td>访问结构指针成员</td> 
   <td>rexp-&gt;member_name</td> 
   <td>lexp</td> 
   <td>L-R</td> 
   <td>否</td> 
  </tr> 
  <tr> 
   <td>++</td> 
   <td>后缀自增</td> 
   <td>lexp++</td> 
   <td>rexp</td> 
   <td>L-R</td> 
   <td>否</td> 
  </tr> 
  <tr> 
   <td>–</td> 
   <td>后缀自减</td> 
   <td>lexp - -</td> 
   <td>rexp</td> 
   <td>L-R</td> 
   <td>否</td> 
  </tr> 
  <tr> 
   <td>！</td> 
   <td>逻辑反</td> 
   <td>！rexp</td> 
   <td>rexp</td> 
   <td>R-L</td> 
   <td>否</td> 
  </tr> 
  <tr> 
   <td>~</td> 
   <td>按位取反</td> 
   <td>~rexp</td> 
   <td>rexp</td> 
   <td>R-L</td> 
   <td>否</td> 
  </tr> 
  <tr> 
   <td>+</td> 
   <td>单目，表示正值</td> 
   <td>+rexp</td> 
   <td>rexp</td> 
   <td>R-L</td> 
   <td>否</td> 
  </tr> 
  <tr> 
   <td>-</td> 
   <td>单目，表示负值</td> 
   <td>-rexp</td> 
   <td>rexp</td> 
   <td>R-L</td> 
   <td>否</td> 
  </tr> 
  <tr> 
   <td>++</td> 
   <td>前缀自增</td> 
   <td>++rexp</td> 
   <td>rexp</td> 
   <td>R-L</td> 
   <td>否</td> 
  </tr> 
  <tr> 
   <td>- -</td> 
   <td>前缀自减</td> 
   <td>- -rexp</td> 
   <td>rexp</td> 
   <td>R-L</td> 
   <td>否</td> 
  </tr> 
  <tr> 
   <td>*</td> 
   <td>间接访问</td> 
   <td>* rexp</td> 
   <td>lexp</td> 
   <td>R-L</td> 
   <td>否</td> 
  </tr> 
  <tr> 
   <td>&amp;</td> 
   <td>取地址</td> 
   <td>&amp; lexp</td> 
   <td>rexp</td> 
   <td>R-L</td> 
   <td>否</td> 
  </tr> 
  <tr> 
   <td>sizeof</td> 
   <td>取其长度，以字节表示</td> 
   <td>sizeof rexp sizeof（类型）</td> 
   <td>rexp</td> 
   <td>R-L</td> 
   <td>否</td> 
  </tr> 
  <tr> 
   <td>（类型）</td> 
   <td>类型转换</td> 
   <td>（类型）rexp</td> 
   <td>rexp</td> 
   <td>R-L</td> 
   <td>否</td> 
  </tr> 
  <tr> 
   <td>*</td> 
   <td>乘法</td> 
   <td>rexp * rexp</td> 
   <td>rexp</td> 
   <td>L-R</td> 
   <td>否</td> 
  </tr> 
  <tr> 
   <td>/</td> 
   <td>除法</td> 
   <td>rexp / rexp</td> 
   <td>rexp</td> 
   <td>L-R</td> 
   <td>否</td> 
  </tr> 
  <tr> 
   <td>%</td> 
   <td>整数取余</td> 
   <td>rexp % rexp</td> 
   <td>rexp</td> 
   <td>L-R</td> 
   <td>否</td> 
  </tr> 
  <tr> 
   <td>+</td> 
   <td>加法</td> 
   <td>rexp + rexp</td> 
   <td>rexp</td> 
   <td>L-R</td> 
   <td>否</td> 
  </tr> 
  <tr> 
   <td>-</td> 
   <td>减法</td> 
   <td>rexp - rexp</td> 
   <td>rexp</td> 
   <td>L-R</td> 
   <td>否</td> 
  </tr> 
  <tr> 
   <td>&lt;&lt;</td> 
   <td>左移位</td> 
   <td>rexp &lt;&lt; rexp</td> 
   <td>rexp</td> 
   <td>L-R</td> 
   <td>否</td> 
  </tr> 
  <tr> 
   <td>&gt;&gt;</td> 
   <td>右移位</td> 
   <td>rexp &gt;&gt; rexp</td> 
   <td>rexp</td> 
   <td>L-R</td> 
   <td>否</td> 
  </tr> 
  <tr> 
   <td>&gt;</td> 
   <td>大于</td> 
   <td>rexp &gt; rexp</td> 
   <td>rexp</td> 
   <td>L-R</td> 
   <td>否</td> 
  </tr> 
  <tr> 
   <td>&gt;=</td> 
   <td>大于等于</td> 
   <td>rexp &gt;= rexp</td> 
   <td>rexp</td> 
   <td>L-R</td> 
   <td>否</td> 
  </tr> 
  <tr> 
   <td>&lt;</td> 
   <td>小于</td> 
   <td>rexp &lt; rexp</td> 
   <td>rexp</td> 
   <td>L-R</td> 
   <td>否</td> 
  </tr> 
  <tr> 
   <td>&lt;=</td> 
   <td>小于等于</td> 
   <td>rexp &lt;= rexp</td> 
   <td>rexp</td> 
   <td>L-R</td> 
   <td>否</td> 
  </tr> 
  <tr> 
   <td>==</td> 
   <td>等于</td> 
   <td>rexp == rexp</td> 
   <td>rexp</td> 
   <td>L-R</td> 
   <td>否</td> 
  </tr> 
  <tr> 
   <td>!=</td> 
   <td>不等于</td> 
   <td>rexp ！= rexp</td> 
   <td>rexp</td> 
   <td>L-R</td> 
   <td>否</td> 
  </tr> 
  <tr> 
   <td>&amp;</td> 
   <td>位与</td> 
   <td>rexp &amp; rexp</td> 
   <td>rexp</td> 
   <td>L-R</td> 
   <td>否</td> 
  </tr> 
  <tr> 
   <td>^</td> 
   <td>位异或</td> 
   <td>rexp ^rexp</td> 
   <td>rexp</td> 
   <td>L-R</td> 
   <td>否</td> 
  </tr> 
  <tr> 
   <td>|</td> 
   <td>位或</td> 
   <td>rexp | rexp</td> 
   <td>rexp</td> 
   <td>L-R</td> 
   <td>否</td> 
  </tr> 
  <tr> 
   <td>&amp;&amp;</td> 
   <td>逻辑与</td> 
   <td>rexp &amp;&amp; rexp</td> 
   <td>rexp</td> 
   <td>L-R</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>||</td> 
   <td>逻辑或</td> 
   <td>rexp ||rexp</td> 
   <td>rexp</td> 
   <td>L-R</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>？：</td> 
   <td>条件操作符</td> 
   <td>rexp？rexp：rexp</td> 
   <td>rexp</td> 
   <td>N/A</td> 
   <td>是</td> 
  </tr> 
  <tr> 
   <td>=</td> 
   <td>赋值</td> 
   <td>lexp=rexp</td> 
   <td>rexp</td> 
   <td>R-L</td> 
   <td>否</td> 
  </tr> 
  <tr> 
   <td>+=</td> 
   <td>以…加</td> 
   <td>lexp += rexp</td> 
   <td>rexp</td> 
   <td>R-L</td> 
   <td>否</td> 
  </tr> 
  <tr> 
   <td>- =</td> 
   <td>以…减</td> 
   <td>lexp - = rexp</td> 
   <td>rexp</td> 
   <td>R-L</td> 
   <td>否</td> 
  </tr> 
  <tr> 
   <td>*=</td> 
   <td>以…乘</td> 
   <td>lexp *= rexp</td> 
   <td>rexp</td> 
   <td>R-L</td> 
   <td>否</td> 
  </tr> 
  <tr> 
   <td>/ =</td> 
   <td>以…除</td> 
   <td>lexp / = rexp</td> 
   <td>rexp</td> 
   <td>R-L</td> 
   <td>否</td> 
  </tr> 
  <tr> 
   <td>%=</td> 
   <td>以…取模</td> 
   <td>lexp %= rexp</td> 
   <td>rexp</td> 
   <td>R-L</td> 
   <td>否</td> 
  </tr> 
  <tr> 
   <td>&lt;&lt; =</td> 
   <td>以…左移</td> 
   <td>lexp &lt;&lt; = rexp</td> 
   <td>rexp</td> 
   <td>R-L</td> 
   <td>否</td> 
  </tr> 
  <tr> 
   <td>&gt;&gt; =</td> 
   <td>以…右移</td> 
   <td>lexp &gt;&gt; = rexp</td> 
   <td>rexp</td> 
   <td>R-L</td> 
   <td>否</td> 
  </tr> 
  <tr> 
   <td>&amp; =</td> 
   <td>以…与</td> 
   <td>lexp &amp;= rexp</td> 
   <td>rexp</td> 
   <td>R-L</td> 
   <td>否</td> 
  </tr> 
  <tr> 
   <td>^ =</td> 
   <td>以…异或</td> 
   <td>lexp ^ = rexp</td> 
   <td>rexp</td> 
   <td>R-L</td> 
   <td>否</td> 
  </tr> 
  <tr> 
   <td>| =</td> 
   <td>以…或</td> 
   <td>lexp |= rexp</td> 
   <td>rexp</td> 
   <td>R-L</td> 
   <td>否</td> 
  </tr> 
  <tr> 
   <td>,</td> 
   <td>逗号</td> 
   <td>rexp，rexp</td> 
   <td>rexp</td> 
   <td>L-R</td> 
   <td>是</td> 
  </tr> 
 </tbody> 
</table>