Detailed example of implementing var_export using PHP

<?php
/**
 * PHP 实现var_export();功能
 */
   $arr = array("1","2","3");
   $arr1 = array(&#39;a&#39;=>NULL,&#39;b&#39;=>array(&#39;1&#39;=>3));
   var_export($arr);
   //var_export($arr1);
  function varExport($arr){
     $ret = "array( ";
     foreach($arr as $k=>$v){
        $ret .= (is_numeric($k) ? $k : "&#39;".$k."&#39;");
        $ret .= &#39; => &#39;;
        $_type = strtolower(gettype($v));
        switch($_type){
           case &#39;integer&#39;:
               $ret .= $v." ,";
               break;
           case &#39;array&#39;:
                $ret .= varExport($v).&#39;,&#39;;
                break;
           case &#39;null&#39;:
                $ret .= "NULL ,";
                break;
           default:
               $ret  .= "&#39;".$v."&#39;,";
               break;
        }
     }
     $ret .= " )";
     return $ret;
  }
  //echo varExport($arr);
   echo varExport($arr);
   //bool is_numeric ( mixed $var )如果 var 是数字和数字字符串则返回 TRUE，否则返回 FALSE 
   //故不能用 is_numeric 验证是否为int类型。。。
?>