JavaScript数据返回类型

约定不等于承诺〃 2022-05-12 05:44 193阅读 0赞

<table style="width:452px;">  JavaScript数据返回类型  
 <thead> 
  <tr> 
   <th style="width:95px;">类型</th> 
   <th style="width:155px;">字面量</th> 
   <th style="width:162px;">typeof()</th> 
   <th style="width:39px;">&nbsp;</th> 
  </tr> 
 </thead> 
 <tbody> 
  <tr> 
   <td style="width:95px;">字符串</td> 
   <td style="width:155px;">'shuhhhg'</td> 
   <td style="width:162px;">string</td> 
   <td style="width:39px;">&nbsp;</td> 
  </tr> 
  <tr> 
   <td style="width:95px;">数字</td> 
   <td style="width:155px;">123</td> 
   <td style="width:162px;">number</td> 
   <td style="width:39px;">&nbsp;</td> 
  </tr> 
  <tr> 
   <td style="width:95px;">布尔</td> 
   <td style="width:155px;">true、false</td> 
   <td style="width:162px;">boolean</td> 
   <td style="width:39px;">&nbsp;</td> 
  </tr> 
  <tr> 
   <td style="width:95px;">空值</td> 
   <td style="width:155px;">null</td> 
   <td style="width:162px;">object</td> 
   <td style="width:39px;">&nbsp;</td> 
  </tr> 
  <tr> 
   <td style="width:95px;">未定义</td> 
   <td style="width:155px;">undefined</td> 
   <td style="width:162px;">undefined</td> 
   <td style="width:39px;">&nbsp;</td> 
  </tr> 
  <tr> 
   <td style="width:95px;">函数</td> 
   <td style="width:155px;">function(){}</td> 
   <td style="width:162px;">function</td> 
   <td style="width:39px;">&nbsp;</td> 
  </tr> 
  <tr> 
   <td style="width:95px;">数组</td> 
   <td style="width:155px;">[ &nbsp; ]</td> 
   <td style="width:162px;">object</td> 
   <td style="width:39px;">&nbsp;</td> 
  </tr> 
  <tr> 
   <td style="width:95px;">对象</td> 
   <td style="width:155px;">{ &nbsp;}</td> 
   <td style="width:162px;">object</td> 
   <td style="width:39px;">&nbsp;</td> 
  </tr> 
  <tr> 
   <td style="width:95px;">日期</td> 
   <td style="width:155px;">new Date</td> 
   <td style="width:162px;">object</td> 
   <td style="width:39px;">&nbsp;</td> 
  </tr> 
  <tr> 
   <td style="width:95px;">正则</td> 
   <td style="width:155px;">/^[A-Z]$/.test()</td> 
   <td style="width:162px;">object</td> 
   <td style="width:39px;">&nbsp;</td> 
  </tr> 
  <tr> 
   <td style="width:95px;">错误</td> 
   <td style="width:155px;">new Error</td> 
   <td style="width:162px;">object</td> 
   <td style="width:39px;">&nbsp;</td> 
  </tr> 
 </tbody> 
</table>

var s=null;
    console.log(typeof(s));
    VM647:2 object
    
    var s=undefined;
    console.log(typeof(s));
    VM683:2 undefined
    
    var s=123;
    console.log(typeof(s));
    VM705:2 number
    
    var s='hope';
    console.log(typeof(s));
    VM740:2 string
    
    var s=true;
    console.log(typeof(s));
    VM791:2 boolean
    
    var s=function(){};
    console.log(typeof(s));
    VM827:2 function
    
    var s=[2];
    console.log(typeof(s));
    VM926:2 object
    
    var s={};
    console.log(typeof(s));
    VM958:2 object