PHP异常学习练习

<?php  class Exception_1 extends Exception  {   private $error;   public function __construct($error)   {    return $this->error=$error;   }  }  class Exception_2 extends Exception  {   private $error;   public function __construct($error)   {    return $this->error=$error;   }  }    class Test_throw  {   public function __construct()   {   // throw new Exception_1(“error-1″);    throw new Exception_2(“error-2″);   // throw new Exception(“error-0″);   }  }    try{   $test=new Test_throw;  }catch(Exception_1 [...]