PHP中的魔术方法总结和使用实例

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<?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;

}

//当给不可访问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;

}

//读取不可访问或不存在属性时被调用

public function __get($name)

{

echo $name;

echo '__get called'.PHP_EOL;

}

//调用不可访问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;

}

//调用不可访问或不存在的静态方法时被调用

public static function __callStatic($name, $arguments)

{

echo $name . '-' . implode(',', $arguments);

echo '__callStatic called'.PHP_EOL;

}

//对不可访问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;

}

//对不可访问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('var1111111111');

}

//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-1,2,3__call called

not_exist_property__isset called

1not_exist_property__unset called

__sleep called

O:5:"Magic":1:{s:13:"var1111111111";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

*/