### __get() 獲得不可訪問的屬性的值： __get() 一旦定義了__get()魔術方法，獲取不可訪問的屬性的值的時候，就會自動的執行該方法，此時，處理權就交給用戶自己了！ 該魔術方法，只需要一個參數，就是該屬性的屬性名！ ### 默認行為 ~~~ class Person{ public $name; public $age; public function __construct($name, $age) { $this->name = $name; $this->age = $age; } } $p = new Person("jack",20); var_dump($p->height); ~~~ ~~~ Notice: Undefined property: Person::$height //報錯 ~~~ ### 不完成方法體 ~~~ class Person{ public $name; public $age; public function __construct($name, $age) { $this->name = $name; $this->age = $age; } public function __get($name) //自動調用__get() ,但是該方法什么都沒做 { } } $p = new Person("jack",20); var_dump($p->height); ~~~ ~~~ NULL ~~~ ### 完成方法體 ~~~ class Person{ public $name; public $age; public function __construct($name, $age) { $this->name = $name; $this->age = $age; } public function __get($name) { if(!isset($this->$name)){ return "屬性不存在"; } } } $p = new Person("jack", 20); var_dump($p->height); ~~~ ~~~ string(15) "屬性不存在" ~~~ 或者 ~~~ class Person{ private $name; private $age; private $money; public function __construct($name) { $this->name = $name; } public function setName($name) { $this->name = $name; } public function __get($name) { $allow_get = ['name', 'age']; if(in_array($name, $allow_get)){ return $this->$name; } return "無權訪問"; } } $p1 = new Person("jack"); var_dump($p1->money); ~~~ ~~~ string(12) "無權訪問" ~~~ ### 注意 __get和__set兩個方法往往在真實的項目中都是成對出現的！而且，往往就是利用這兩個方法批量的對對象的私有屬性進行處理！