**一.父子类使用过程中，同名方法的参数类型规则：子类的参数类型要包含父类的参数类型** ``` class Person{ public function show(int $name){ } } class User extends Person{ public function show($name){ } } ```   **二.子类同名方法的参数类型不包含父类方法的参数类型** 1.普通 ``` class Foo { public function process(int $item): array{} } class SuperFoo extends Foo{ public function process(string $items): array{} } ``` 2.抽象 ``` abstract class Person{ abstract function show(int $name); } class User extends Person{ public function show(string $name){ } } ```   **三.trait中同名普通方法参数可不同** ``` trait Foo { public function inParams(int $item){ } } class SuperFoo{ use Foo; public function inParams(string $items){ } } ```   **四.trait中同名抽象方法参数类型必须相同** ``` trait Person { abstract function show(int $name); } class User{ use Person; public function show(mixed $name){ } } ```   **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)