php的static延迟加载

<?php
abstract class Food
{
    private $cups;
    protected $apples;
    protected $water;

    function __construct(){
        $this->cups = static::getCups();//static 也可以调用其他static修饰的函数
        $this->apples = static::getApple();
        $this->water = $this->getWater();
    }

    static function create(){
        return new static();
    }

    static function getCups(){
        return ‘debault‘;
    }

    static function getApple(){
        return "apple";
    }

    protected function getWater(){
        return "water";
    }
}

class People extends Food
{
    static function getCups(){
        return "Please give me a big bottles";
    }

    static function getApple(){
        return "Please give me a big apple";
    }    
}

echo "<pre>";
$app = People::create();
var_dump($app);
var_dump($app::getCups());
echo "</pre>";
?>