<?php
class Car {
??? public $speed = 0; //汽車的起始速度是0
???
??? public function speedUp() {
??????? $this->speed += 10;
??????? return $this->speed;
??? }
}
//定義繼承于Car的Truck類
class Truck extends Car{
??? public function speedUp(){
??????? $this->speed = parent::speedUp() + 50;
???????
??? }
???
}

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

重載應(yīng)該是子類方法調(diào)用__call，__call調(diào)用父類方法吧，我覺得