个回答

• 慕姐4207973

  2016-03-29 12:25:57

  <?php
  class Car {
      public $speed = 0; //汽车的起始速度是0
     
      public function speedUp() {
          $this->speed += 10;
          return $this->speed;
      }
  }
  //定义继承于Car的Truck类
  class Truck extends Car{
      public function speedUp(){
          $this->speed = parent::speedUp() + 50;
         
      }
     
  }

  $car = new Truck();
  $car->speedUp();
  echo $car->speed;

  0

• 山蛋蛋

  2016-03-29 12:21:51

  重载应该是子类方法调用__call，__call调用父类方法吧，我觉得
  

  0