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HomeBackend DevelopmentPHP Tutorial 函数参数:true?该怎么解决

函数参数:true?

本帖最后由 u012362664 于 2013-10-09 20:35:48 编辑
<br />
<?<br />
<br />
     $x1=array(1=>111,2=>12,3=>3333);<br />
     $y1=in_array(12,$x1,true);<br />
     echo $y1;<br />
     echo "\r\n";<br />
     <br />
     $x2=array(1=>111,2=>12,3=>3333);<br />
     $y2=in_array('12',$x2,true);     <br />
     echo $y2;<br />
     echo "\r\n";<br />
     <br />
     $x3=array(1=>111,2=>12,3=>3333);<br />
     $y3=in_array("12",$x3,true);    <br />
     echo $y3;<br />
     echo "\r\n";<br />
    <br />
?><br />


程序输出:
1
0
0


问题:
1.上面程序编译,没语法错误。
   函数in_array( ),第1个参数,都是int整型。

   函数in_array( ),第3个参数:true,有什么作用?
   
   为什么,第1个数组,返回结果:1,找到。
   每2,3个数组,返回结果:0,找不到?
  

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