PHP中的__set和__get方法

<?php
class HandsonBoy
{
    private $name = ‘chenqionghe‘;
    private $age = 18;
    public function __set($name,$value)
    {
        echo ‘您正在设置私有属性‘.$name.‘<br >值为‘.$value.‘<br>‘;
        $this->$name = $value;
    }
    public function __get($name)
    {
        if(!isset($this->$name))
        {
            echo ‘未设置‘.$name;
            $this->$name = "正在为你设置默认值".‘<br>‘;
        }
        return $this->$name;
    }
}
$a = new HandsonBoy();
echo $a->name.‘<br />‘;
$a->hair = ‘short‘;