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     }
     }
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    unset($test1);
    echo "<hr/>";

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    <?php 
    /* 
     * Created on 2009-11-18 
     * 
     * To change the template for this generated file go to 
     * Window - Preferences - PHPeclipse - PHP - Code Templates 
     */ 
     class student{ 
     //ÊoÐÔ 
     private $no; 
     private $name; 
     private $gender; 
     private $age; 

     private static $count=0; 
     function __construct($pname) 
     { 
     $this->name = $pname; 
     self::$count++; 
     } 

     function __destruct() 
     { 
     self::$count--; 
     } 

     static function get_count() 
     { 
     return self::$count; 
     } 
     } 

     $s1=new student("Tom"); 
     print(student::get_count()); 

     $s2=new student("jerry"); 
     print(student::get_count()); 

     $s1=NULL; 
     print(student::get_count()); 

     $s2=NULL; 
     print(student::get_count()); 
    ?> 

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