PHP use闭包函数

<?php

class Cart

{

//产品价格

const PRICE_BUTTER = 1.00;

const PRICE_MILK = 3.00;

const PRICE_EGGS = 6.95;

protected $products =array();

public function add($product,$quantity)

{

$this->products[$product] = $quantity;

}

public function getQuantity($product)

{

return isset($this->products[$product]) ? $this->products[$product] :

FALSE;

}

public function getTotal($tax)

{

$total = 0.00;

$callback =

function ($quantity,$product)use ($tax, &$total)

{

// echo __CLASS__ ."::PRICE_" . strtoupper($product);die;

$pricePerItem = constant(__CLASS__ ."::PRICE_" . strtoupper($product));

// echo $pricePerItem.'<br>';

$total += ($pricePerItem *$quantity) * ($tax + 1.0);

};

array_walk($this->products,$callback);

return round($total, 2);

}

}

$my_cart =new Cart;

// 往购物车里添加条目

$my_cart->add('butter', 1);

$my_cart->add('milk', 3);

$my_cart->add('eggs', 6);

// 打出出总价格，其中有 5% 的销售税.

print $my_cart->getTotal(0.05) . "\n";

// The result is 54.29

?>