**一.static类型作用** PHP 8.0允许static作为类方法的返回类型.   **二.static语法** ``` class Foo { public static function getInstance(): static { return new static(); } } ```   **三.仅返回类型** static返回类型仅允许作为返回类型。不允许将其作为属性类型或参数类型.   **四.不允许在类外使用** 只有类方法可以声明static返回类型。标准函数或闭包不允许声明static返回类型.   **五.实用代码实例** 1.对象链设计 ``` class Person{ public function say(){ return $this; } public function show(){ return $this; } public function look(){ echo 'say->show->look->echo'; } } $obj=new Person; $obj->say()->show()->look(); ``` 2.类链设计 ``` class Person{ public static function say():static{ return new static(); } public static function show():static{ return new static(); } public static function look(){ echo 'Person::say()::show()::look() echo'; } } Person::say()::show()::look(); ``` 3.类输出静态方法中的类常量 ``` class Person{ const HOST='localhost'; public static function say(){ return self::HOST; } } echo Person::say(); ```   **配套的PHP8新特性详解视频教程，请查看以下专辑** 链接：[https://www.ixigua.com/6937490165329822219](https://www.ixigua.com/6937490165329822219)