PHP基础之类和对象16——Final关键字

Example #1 Final 方法示例

class BaseClass
{
    public function test(){
        echo "BaseClass::test() called<br>";
    }

    final public function moreTesting(){
        echo "BaseClass::moreTesting() called<br>";
    }
}
class ChildClass extends BaseClass
{
    public function moreTesting(){
        echo "BaseClass::moreTeing called<br>";
    }
}

Example #2 Final 类示例

final class BaseClass{
    public function test(){
        echo "BaseClass::test() called\n";
    }

    //这里无论你是否将方法声明为final，都没有关系
    final public function moreTesting(){
        echo "BaseClass::moreTesting() called\n";
    }
}
class ChildClass extends BaseClass{}

//产生Fatal Error:Class ChildClass may not inherit from final class (BaseClass)

Note: 属性不能被定义为 final，只有类和方法才能被定义为 final。