继承引入参数

      name = $name;        $this->age = $age;        $this->time=date("Ymd");    }    /**     * @return mixed     */    public function hello()    {        echo $this->time;    }}class B extends A{    private static $name = '123';    private static $age = 12;    public function __construct()    {        parent::__construct(self::$name, self::$age);    }}$obj = new B();echo $obj->hello();

实例化引入重写

      name = $name;        $this->age = $age;        $this->time=date("Ymd");    }    /**     * @return mixed     */    public function hello()    {        echo $this->time;    }}class B{    public static $a;    public function __construct()    {        $name='jack';        $age=23;        self::$a=new A($name,$age);    }    public function test(){        echo self::$a->time;    }}$obj = new B();$obj->test();