PHP使用接口的好处之一_PHP_编程开发_程序员俱乐部

interface Isay {
    public function say();
}

class hello implements Isay{
    public function say(){
        echo "hello";
    }
}

class world implements Isay{
    public function say(){
        echo "world";
    }
}

function test_say(Isay $isay){
    $isay->say();
}

test_say(new hello());    //output:"hello"
test_say(new world());    //output:"world"