PHP魔術(shù)方法使用方法匯總
魔術(shù)方法是PHP面向?qū)ο笾刑赜械奶匦?。它們?cè)谔囟ǖ那闆r下被觸發(fā),都是以雙下劃線開(kāi)頭,你可以把它們理解為鉤子,利用模式方法可以輕松實(shí)現(xiàn)PHP面向?qū)ο笾兄剌d(Overloading即動(dòng)態(tài)創(chuàng)建類屬性和方法)。魔術(shù)方法很多還是成對(duì)出現(xiàn)的,以下列出目前PHP中所有的模式方法。
1.__construct,__destruct
__constuct構(gòu)建對(duì)象的時(shí)被調(diào)用;
__destruct明確銷毀對(duì)象或腳本結(jié)束時(shí)被調(diào)用;
2.__get,__set
__set當(dāng)給不可訪問(wèn)或不存在屬性賦值時(shí)被調(diào)用
__get讀取不可訪問(wèn)或不存在屬性時(shí)被調(diào)用
3.__isset,__unset
__isset對(duì)不可訪問(wèn)或不存在的屬性調(diào)用isset()或empty()時(shí)被調(diào)用
__unset對(duì)不可訪問(wèn)或不存在的屬性進(jìn)行unset時(shí)被調(diào)用
4.__call,__callStatic
__call調(diào)用不可訪問(wèn)或不存在的方法時(shí)被調(diào)用
__callStatic調(diào)用不可訪問(wèn)或不存在的靜態(tài)方法時(shí)被調(diào)用
5.__sleep,__wakeup
__sleep當(dāng)使用serialize時(shí)被調(diào)用,當(dāng)你不需要保存大對(duì)象的所有數(shù)據(jù)時(shí)很有用
__wakeup當(dāng)使用unserialize時(shí)被調(diào)用,可用于做些對(duì)象的初始化操作
6.__clone
進(jìn)行對(duì)象clone時(shí)被調(diào)用,用來(lái)調(diào)整對(duì)象的克隆行為
7.__toString
當(dāng)一個(gè)類被轉(zhuǎn)換成字符串時(shí)被調(diào)用
8.__invoke
當(dāng)以函數(shù)方式調(diào)用對(duì)象時(shí)被調(diào)用
9.__set_state
當(dāng)調(diào)用var_export()導(dǎo)出類時(shí),此靜態(tài)方法被調(diào)用。用__set_state的返回值做為var_export的返回值。
10.__debuginfo
當(dāng)調(diào)用var_dump()打印對(duì)象時(shí)被調(diào)用(當(dāng)你不想打印所有屬性)適用于PHP5.6版本
PHP魔術(shù)方法使用實(shí)例如下:
<?php
class Magic
{
public $var = 'test';
//構(gòu)造函數(shù),在創(chuàng)建對(duì)象的時(shí)候調(diào)用
public function __construct()
{
echo '__construct called'.PHP_EOL;
}
//某個(gè)對(duì)象的引用都被刪除、對(duì)象被銷毀、調(diào)用exit()后、腳本關(guān)閉時(shí)被調(diào)用
public function __destruct()
{
echo '__destruct called'.PHP_EOL;
}
//當(dāng)給不可訪問(wèn)或不存在屬性賦值時(shí)被調(diào)用
public function __set($name, $value)
{
echo $name.'-'.$value;
echo '__set called'.PHP_EOL;
}
//讀取不可訪問(wèn)或不存在屬性時(shí)被調(diào)用
public function __get($name)
{
echo $name;
echo '__get called'.PHP_EOL;
}
//調(diào)用不可訪問(wèn)或不存在的方法時(shí)被調(diào)用
public function __call($name, $arguments)
{
echo $name . '-' . implode(',', $arguments);
echo '__call called'.PHP_EOL;
}
//調(diào)用不可訪問(wèn)或不存在的靜態(tài)方法時(shí)被調(diào)用
public static function __callStatic($name, $arguments)
{
echo $name . '-' . implode(',', $arguments);
echo '__callStatic called'.PHP_EOL;
}
//對(duì)不可訪問(wèn)或不存在的屬性調(diào)用isset()或empty()時(shí)被調(diào)用
public function __isset($name)
{
echo $name;
echo '__isset called'.PHP_EOL;
return true;
}
//對(duì)不可訪問(wèn)或不存在的屬性進(jìn)行unset時(shí)被調(diào)用
public function __unset($name)
{
echo $name;
echo '__unset called'.PHP_EOL;
}
//serialize時(shí)被調(diào)用,當(dāng)你不需要保存大對(duì)象的所有數(shù)據(jù)時(shí)很有用
public function __sleep()
{
echo '__sleep called'.PHP_EOL;
return array('var1111111111');
}
//unserialize時(shí)被調(diào)用,可用于做些對(duì)象的初始化操作
public function __wakeup()
{
echo '__wakeup called'.PHP_EOL;
$this->var = 'test after wakeup';
}
//當(dāng)一個(gè)類被轉(zhuǎn)換成字符串時(shí)被調(diào)用
public function __toString()
{
return '__toString called'.PHP_EOL;
}
//進(jìn)行對(duì)象clone時(shí)被調(diào)用,用來(lái)調(diào)整對(duì)象的克隆行為
public function __clone()
{
echo '__clone called'.PHP_EOL;
}
//當(dāng)以函數(shù)方式調(diào)用對(duì)象時(shí)被調(diào)用
public function __invoke()
{
echo '__invoke called'.PHP_EOL;
}
//當(dāng)調(diào)用var_export()導(dǎo)出類時(shí),此靜態(tài)方法被調(diào)用。用__set_state的返回值做為var_export的返回值。
public static function __set_state($arr)
{
return '__set_state called'.PHP_EOL;
}
//當(dāng)調(diào)用var_dump()打印對(duì)象時(shí)被調(diào)用(當(dāng)你不想打印所有屬性)適用于PHP5.6版本
public function __debuginfo($arr)
{
echo '__debuginfo called'.PHP_EOL;
return array(
'var' => 'test fro __debuginfo'
);
}
}
$m = new Magic(); //__construct()被調(diào)用
$m->not_exist_property = test; //__set()被調(diào)用
echo $m->not_exist_property;//__get()被調(diào)用
$m->abc(1,2,3); //__call()被調(diào)用
echo isset($m->not_exist_property); //__isset()被調(diào)用,返回bool值
unset($m->not_exist_property); //__unset()被調(diào)用
echo $tmp = serialize($m); //__sleep()被調(diào)用
unserialize($tmp); //__wakeup()被調(diào)用
$m1 = clone $m; //__clone()被調(diào)用,對(duì)象默認(rèn)是引用傳遞,使用clone關(guān)鍵詞則可實(shí)現(xiàn)對(duì)象復(fù)制
$m(); //__invoke()
eval( '$m2 = ' . var_export ( $m , true ) . ';' );var_dump($m2);
var_dump($m);
//最后__destruct()被調(diào)用
/*
結(jié)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
*/
以上就是關(guān)于PHP魔術(shù)方法使用方法的全部?jī)?nèi)容,希望對(duì)大家的學(xué)習(xí)有所幫助。
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