PHP中的魔术方法总结和使用实例

PHP实例
<?php
 
class Magic
{
  public $var = 'test';
 
  //构造函数,在创建对象的时候调用
  public function __construct()
  {
    echo '__construct called'.PHP_EOL;
  }
 
  //某个对象的引用都被删除、对象被销毁、调用exit()后、脚本关闭时被调用
  public function __destruct()
  {
    echo '__destruct called'.PHP_EOL;
  }
 
  //当给不可拜访或不存在属性赋值时被调用
  public function __set($name,$value)
  {
    echo $name.'-'.$value;
    echo '__set called'.PHP_EOL;
  }
 
  //读取不可拜访或不存在属性时被调用
  public function __get($name)
  {
    echo $name;
    echo '__get called'.PHP_EOL;
  }
 
  //调用不可拜访或不存在的方法时被调用
  public function __call($name,$arguments)
  {
    echo $name . '-' . implode(',',$arguments);
    echo '__call called'.PHP_EOL;
  }
 
  //调用不可拜访或不存在的静态方法时被调用
  public static function __callStatic($name,$arguments);
    echo '__callStatic called'.PHP_EOL;
  }
 
  //对不可拜访或不存在的属性调用isset()或empty()时被调用
  public function __isset($name)
  {
    echo $name;
    echo '__isset called'.PHP_EOL;
    return true;
  }
 
  //对不可拜访或不存在的属性进行unset时被调用
  public function __unset($name)
  {
    echo $name;
    echo '__unset called'.PHP_EOL;
  }
 
  //serialize时被调用,当你不需要保存大对象的所有数据时很有用
  public function __sleep()
  {
    echo '__sleep called'.PHP_EOL;
    return array('var2222222222');
  }
 
  //unserialize时被调用,可用于做些对象的初始化操作
  public function __wakeup()
  {
    echo '__wakeup called'.PHP_EOL;
    $this->var = 'test after wakeup';
  }
 
  //当一个类被转换成字符串时被调用
  public function __toString()
  {
    return '__toString called'.PHP_EOL;
  }
 
  //进行对象clone时被调用,用来调整对象的克隆行为
  public function __clone()
  {
    echo '__clone called'.PHP_EOL;
  }
 
  //当以函数方式调用对象时被调用
  public function __invoke()
  {
    echo '__invoke called'.PHP_EOL;
  }
 
  //当调用var_export()导出类时,此静态方法被调用.用__set_state的返回值做为var_export的返回值.
  public static function __set_state($arr)
  {
    return '__set_state called'.PHP_EOL;
  }
 
  //当调用var_dump()打印对象时被调用(当你不想打印所有属性)适用于PHP5.6版本
  public function __debuginfo($arr)
  {
    echo '__debuginfo called'.PHP_EOL;
    return array(
      'var' => 'test fro __debuginfo'
    );
  }
}
 
$m = new Magic(); //__construct()被调用
$m->not_exist_property = test; //__set()被调用
echo $m->not_exist_property;//__get()被调用
$m->abc(1,2,3); //__call()被调用
echo isset($m->not_exist_property); //__isset()被调用,返回bool值
unset($m->not_exist_property); //__unset()被调用
echo $tmp = serialize($m); //__sleep()被调用
unserialize($tmp); //__wakeup()被调用
$m1 = clone $m; //__clone()被调用,对象默认是引用传递,使用clone关键词则可实现对象复制
$m(); //__invoke()
eval( '$m2 = ' . var_export ( $m,true ) . ';' );var_dump($m2);
var_dump($m);
//最后__destruct()被调用
 
/*
结果：
__construct called
not_exist_property-test__set called
not_exist_property__get called
abc-1,3__call called
not_exist_property__isset called
1not_exist_property__unset called
__sleep called
O:5:"Magic":1:{s:13:"var2222222222";N;}__wakeup called
__destruct called
__clone called
__invoke called
string(20) "__set_state called
"
class Magic#1 (1) {
 public $var =>
 string(4) "test"
}
__destruct called
__destruct called
 
 
*/