__get和__set代码的问题

Question

我不知道我在哪里做错了。有人可以告诉我吗？

<?php 
    class something 
    { 
     public $attr1; 
     private $attr2; 

     public function __get($name) 
     { 
      return $this->$name; 
     } 

     public function __set($name,$value) 
     { 
      $this->$name = $value." added something more"; 
     } 
    } 

    $a = new something(); 

    $a->$attr1 = "attr1"; 
    $a->$attr2 = "attr2"; 

    echo $a->$attr1; //what I would expect is attr1 as output 
    echo $a->$attr2; //what I would expect is attr2 added something more as output 
?> 

Answer 1

访问对象的属性时，请取下的$的多个实例：

$a->$attr1 = "attr1";   $a->attr1 = "attr1"; 
$a->$attr2 = "attr2";   $a->attr2 = "attr2"; 

echo $a->$attr1;    echo $a->attr1; 
echo $a->$attr2;    echo $a->attr2;