**一.ReflectionFunction::isDisabled弃用** 1.禁用函数 #php.ini ``` disable_functions=substr ``` 1.低版本 #Method ReflectionFunction::isDisabled() is deprecated ``` $ref=new ReflectionFunction('substr'); var_dump($ref->isDisabled()) ``` 2.新版本 #true ``` $ref=new ReflectionFunction('substr'); var_dump($ref->isDisabled()) ```   **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)