PHP’s understanding of magic methods

php’s understanding of magic methods: 1. Automatically set the attribute when the [_set] attribute does not exist; 2. When the [__get] attribute does not exist or cannot be read, set this method to be readable; 3. [ __call】When the method does not exist, it is executed; 4. [__callStatic] When the static method does not exist, it is executed.

php's understanding of magic methods:

1, _set: The attribute does not exist Automatically set attributes when

/**
* 属性不存在时通过__set自动设置属性
* @param $key [键名]
* @param $value [属性值]
*/
function __set($key,$value){
$this->arr[$key] = $value;
}
 
代码：
$object->title = 'blue'; //设置不存在的属性，调用__set()
echo $object->title,&#39;<br/>&#39;; //输出不存在的属性，调用__get()
 
输出：
blue

2, __get: When the attribute does not exist or cannot be read, set this method to read

/**
* 属性不存在或不能读取（属性为私有private）时，通过__get读取
* @param $key 键名
* @return 属性
*/
function __get($key){
return $this->arr[$key];
}

3, __call: When the method does not exist, execute

/**
* 方法不存在时，执行__call方法
* @param $func [方法名]
* @param $param [参数]
* @return [description]
*/
function __call($func,$param){
var_dump($func);
echo &#39;<br/>&#39;;
var_dump($param);
echo &#39;<br/>&#39;;
}
 
代码：
$object -> show(&#39;hello&#39;,&#39;world&#39;); //调用不存在的方法，调用__call()
 
输出：
string(4) "show"
array(2) { [0]=> string(5) "hello" [1]=> string(5) "world" }

4, __callStatic: When the static method does not exist, execute

/**
* 静态方法不存在时，执行__callStatic方法
* @param $func [方法名]
* @param $param [参数]
* @return [description]
*/
static function __callStatic($func,$param){
var_dump($func);
echo &#39;<br/>&#39;;
var_dump($param);
echo &#39;<br/>&#39;;
}
 
代码：
IMooc\Object::show(&#39;hello&#39;,&#39;world&#39;); //调用不存在的静态方法，调用__callStatic()
 
输出：
string(4) "show"
array(2) { [0]=> string(5) "hello"  [1]=>string(5) "world" }

5, __toString: When the object is converted to a string, execute

/**
* 当对象转换为字符串时，执行__toString方法
* @return string [description]
*/
function __toString{
return __CLASS__;
}
 
代码：
echo $object,&#39;<br/>&#39;; //将对象以字符串形式输出，调用__toString()
 
输出：
IMooc\Object

6, __invoke: When the object is used as a function, execute

/**
* 当把对象当成函数来使用时，执行__invoke方法
* @param [type] $param [参数]
* @return [type] [description]
*/
function __invoke($param){
var_dump($param);
}
 
代码：
echo $object('hello'); //将对象当函数使用，调用__invoke()
 
输出：
string(5) "hello"

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