How to use php magic methods __get() and __set()

"__set()" is automatically called when assigning a value to an undefined attribute, the syntax is "public function __set(key,value){}"; "__get()" is called when an undefined attribute is called, Syntax "public function __get(name){}".

The operating environment of this tutorial: windows7 system, PHP7.1 version, DELL G3 computer

The magic method in PHP usually starts with __( It starts with two underscores) and does not need to be explicitly called but is automatically called under certain conditions.

1. __set() method

When assigning a value to a class attribute that is undefined or invisible in the current environment, the __set() method will be automatically called. The syntax format for defining this method is as follows:

public function __set($key, $value){ ... ... ; }

Among them, the parameter $key is the name of the variable to be operated, and $value is the value of the variable $key.

[Example] The following uses a simple example to demonstrate the use of the __set() method.

'; } } $object = new Website(); $object -> name = 'php中文网'; $object -> url = '//m.sbmmt.com/'; $object -> title = 'PHP教程'; ?>

The running results are as follows:

为“url”赋值“//m.sbmmt.com/”失败！ 为“title”赋值“PHP教程”失败！

Using the characteristics of the __set() method, we can use the __set() method to assign or modify the attributes modified with the private keyword in the class. . As shown below:

$key)){ $this -> $key = $value; }else{ echo '为“'.$key.'”赋值“'.$value.'”失败！
'; } } public function getUrl(){ echo $this -> url; } } $object = new Website(); $object -> name = 'php中文网'; $object -> url = '//m.sbmmt.com/'; $object -> title = 'PHP教程'; $object -> getUrl(); ?>

The running results are as follows:

为“title”赋值“PHP教程”失败！ //m.sbmmt.com/

2. The __get() method

is not defined or is not defined when calling or obtaining the current environment. When the class attribute is invisible, the __get() method will be automatically called. The syntax format for defining this method is as follows:

public function __get($name){ ... ... ; }

The parameter $name is the name of the variable to be operated.

[Example] The following uses a simple example to demonstrate the use of the __get() method.

 url.'
'; echo $object -> name.'
'; echo $object -> title.'
'; ?>

The running results are as follows:

//m.sbmmt.com/ 获取：“name”失败！ 获取：“title”失败！

Recommended learning: "PHP Video Tutorial"

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