Examples of using PHP magic methods_PHP tutorial

Examples of using PHP magic methods

This article mainly introduces examples of using PHP magic methods. This article explains __get, __set, __call, __callStatic, __toString, __invoke respectively. For the use of magic methods, friends in need can refer to it

　① __get/__set: Take over the properties of the object

When accessing a non-existent object property:

index.php

The code is as follows:

define('BASEDIR',__DIR__); //Define root directory constants

include BASEDIR.'/Common/Loader.php';

spl_autoload_register('\Common\Loader::autoload');

$obj = new CommonObject();

//When accessing a non-existent object property in php

echo $obj->title;

Will throw an error: Notice: Undefined property: CommonObject::$title in D:practisephpdesignpsr0index.php on line 9

After adding the __set and __get methods in Common/Object.php

Object.php

The code is as follows:

namespace Common;

class Object{

Function __set($key,$value){

　}

Function __get($key){

　}

　}

Execute index.php again and no more errors will be reported.

Modify Common/Object.php again

The code is as follows:

namespace Common;

class Object{

　protected $array = array();

Function __set($key,$value){

var_dump(__METHOD__);

$this->array[$key] = $value;

　}

Function __get($key){

var_dump(__METHOD__);

return $this->array[$key];

　}

　}

index.php

The code is as follows:

define('BASEDIR',__DIR__); //Define root directory constants

include BASEDIR.'/Common/Loader.php';

spl_autoload_register('\Common\Loader::autoload');

$obj = new CommonObject();

$obj->title = 'hello';

echo $obj->title;

Execute index.php, page output:

The code is as follows:

String 'CommonObject::__set' (length=20)

String 'CommonObject::__get' (length=20)

Hello

　② __call/__callStatic: Control the invocation of PHP object methods (__callStatic is used to control static methods of classes)

When executing a non-existent php method

index.php:

The code is as follows:

define('BASEDIR',__DIR__); //Define root directory constants

include BASEDIR.'/Common/Loader.php';

spl_autoload_register('\Common\Loader::autoload');

$obj = new CommonObject();

//When executing a non-existent php method

$obj->test('hello',123);

Executing index.php will report a fatal error: Fatal error: Call to undefined method CommonObject::test() in D:practisephpdesignpsr0index.php on line 9

If you define a __call method in Common/Object, it will automatically call back when the method does not exist:

The code is as follows:

namespace Common;

class Object{

Function __call($func, $param){ //$func method name $param parameter

var_dump($func, $param);

Return "magic functionn"; //Return a string as the return value

　}

　}

index.php

The code is as follows:

define('BASEDIR',__DIR__); //Define root directory constants

include BASEDIR.'/Common/Loader.php';

spl_autoload_register('\Common\Loader::autoload');

$obj = new CommonObject();

//When executing a non-existent php method

echo $obj->test('hello',123);

Page output:

The code is as follows:

　string 'test' (length=4)

array

　0 => string 'hello' (length=5)

　1 => int 123

　magic function

When calling a non-existent static method

Common/Object.php

The code is as follows:

namespace Common;

class Object{

static function __callStatic($name, $arguments) {

var_dump($name, $arguments);

Return "magic functionn"; //Return a string as the return value

　}

　}

Note: The __callStatic method must also be declared as a static method

index.php

The code is as follows:

define('BASEDIR',__DIR__); //Define root directory constants

include BASEDIR.'/Common/Loader.php';

spl_autoload_register('\Common\Loader::autoload');

//Execute a non-existent static method

echo CommonObject::test("hello",1234);

Execute index.php, page output:

The code is as follows:

　string 'test' (length=4)

array

　0 => string 'hello' (length=5)

　1 => int 1234

　magic function

　③ __toString: Convert a PHP object into a string

index.php

The code is as follows:

define('BASEDIR',__DIR__); //Define root directory constants

include BASEDIR.'/Common/Loader.php';

spl_autoload_register('\Common\Loader::autoload');

$obj = new CommonObject();

echo $obj;

An error will be reported at this time: Catchable fatal error: Object of class CommonObject could not be converted to string in D:practisephpdesignpsr0index.php on line 8

Add __toString method in Object.php

The code is as follows:

namespace Common;

class Object{

Function __toString() {

return __CLASS__;

　}

　}

　④ __invoke: When a PHP object is executed as a function, this magic method will be called back

index.php

The code is as follows:

define('BASEDIR',__DIR__); //Define root directory constants

include BASEDIR.'/Common/Loader.php';

spl_autoload_register('\Common\Loader::autoload');

$obj = new CommonObject();

echo $obj("test");

Object.php

The code is as follows:

namespace Common;

class Object{

Function __invoke($param) {

var_dump($param);

return 'invoke';

　}

　}

Page output:

The code is as follows:

　string 'test' (length=4)

Invoke

http://www.bkjia.com/PHPjc/1020268.htmlwww.bkjia.comtruehttp: //www.bkjia.com/PHPjc/1020268.htmlTechArticleExamples of using PHP magic methods. This article mainly introduces examples of using PHP magic methods. This article explains each_ _get, __set, __call, __callStatic, __toString, __invoke and other magic squares...