PHP 多态演示

<?php

/**
* 多态
*/
class Animal
{

function __construct()
{
# code...
}

function foo(){
echo "叫";
}
}

class Cat extends Animal{
function foo(){
echo "猫叫";
}
}

class Dog extends Animal{
function foo(){
echo "狗叫";
}
}

//数组提示
function text(array $animal){
// if($animal instanceof Animal){
// $animal->foo();
// }else{
// echo "no Animal";
// }
if(!empty($animal)){
foreach ($animal as $key => $value) {
if($value instanceof Animal){
$value->foo();
}
}
}
}

text(array(new Dog(),new Cat()));

?>