​x
 
<!DOCTYPE html>
<html>
<body>
​
<?php
// 接口定义
interface Animal {
  public function makeSound();
}
​
// 类定义
class Cat implements Animal {
  public function makeSound() {
    echo " 喵 ";
  }
}
​
class Dog implements Animal {
  public function makeSound() {
    echo " 汪汪 ";
  }
}
​
class Mouse implements Animal {
  public function makeSound() {
    echo " 吱吱 ";
  }
}
​
// 创建一个动物列表
$cat = new Cat();
$dog = new Dog();
$mouse = new Mouse();
$animals = array($cat, $dog, $mouse);
​
// 让动物们发出声音
foreach($animals as $animal) {
  $animal->makeSound();
}
?>
 
</body>
</html>