作业1

这里定义了一个抽象类Animal

<?php
abstract class Animal{
    public abstract function  roar() ;
    public function speak( $what )
    {
        echo $what."<br/>" ;
    }
}

接下来是三个类的定义

<?php

require_once "Animal.php" ;

class Pig extends Animal
{
    public function roar()
   {
      $this->speak("I'm a pig!") ;
   }
}
class Monkey extends Animal
{
    public function roar()
    {
        $this->speak("I'm a monkey!") ;
    }
}
class Dog extends Animal
{
    public function roar()
    {
        $this->speak("I'm a dog!") ;
    }
}

接下来定义一个测试函数，并进行测试。

<? php
function test()
{
    $myDog = new Dog() ;
    $myMonkey = new Monkey() ;
    $myPig = new Pig() ;
    $myDog ->roar() ;
    $myMonkey ->roar() ;
    $myPig ->roar() ;
}
test() ;

测试结果为：
I'm a dog!
I'm a monkey!
I'm a pig!

作业2

先定义两个接口

<?php
interface iTalkable
{
    public function talk() ;
}

interface iPlayable
{
    public function play() ;
}

再在抽象类People中实现接口中的方法：

<?php
require_once "InterfaceContainer.php" ;
abstract class People implements iTalkable,iPlayable
{
   public function play()
   {
       echo "I'm playing!"."<br/>" ;
   }
   public function talk(  )
   {
       echo "I'm talking!"."<br/>" ;
   }
}

最后由Teacher类继承People类，并在其中进行测试

<?php
require_once "People.php" ;
class Teacher extends People
{
    public function Teachertalk( $what )
    {
        echo $what."<br/>" ;
    }
    // ……
}
$myTeacher = new Teacher() ;
$myTeacher->play() ;
$myTeacher->Teachertalk("I'm the father of Kai.Z!" ) ;
$myTeacher->talk() ;

结果为：
I'm playing!
I'm the father of Kai.Z!
I'm talking!