时间：2014年4月13日09:46:13 购物车类

<?php

/**

*  Created by PhpStorm.

*  User: Administrator

*  Date: 14-4-13

*  Time: 上午9:49

*/

/*开启会话*/

defined(‘ACC‘) || exit(‘ACC Denied‘);

class CartTool{

private static$ins = null;

/*用数组保存商品*/

private$items = array();

// public $sign = 0;

/*保护构造方法*/

finalprotectedfunction__construct(){

//$this->sign = mt_rand(0,9999999);

}

/*保护克隆方法*/

finalprotectedfunction__clone(){}

/*单例方法获取实例*/

protectedstaticfunctiongetIns(){

if(!(self::$ins instanceof self)){

self::$ins = new self();

}

return self::$ins;

}

/*把购物车的单例对象，放到session中整个网站都共享此实例*/

publicstaticfunctiongetCart(){

/**/

if(!isset($_SESSION[‘cart‘]) || !($_SESSION[‘cart‘] instanceof self)){

$_SESSION[‘cart‘] =  self::getIns();

}

return $_SESSION[‘cart‘];

}

/*添加商品

@param intid 商品主键

@param string name 商品名称

@param float price 商品价格

@param int num 购物数量 */

publicfunctionaddItem($id,$name,$price,$num = 1){

/*商品id 唯一，作为数组下表此时数组已经作为二维数组*/

if($this->hasItem($id)){

/*如果该商品已经存在，则直接加其数量*/

$this->incNum($id,$num);

return;

}

$item = array();

$item[‘name‘] = $name;

$item[‘price‘] = $price;

$item[‘num‘] = $num;

$this->items[$id] =$item;

}

/*清空购物车*/

publicfunctionclear(){

$this->items = array();

}

/*判断某个商品是否存在*/

publicfunctionhasItem($id){

return array_key_exists($id,$this->items);

}

/*修改商品数量

@param int id 商品主键

@param int num 某个商品修改后的数量，即直接把商品数量修改为num*/

publicfunctionmodNum($id,$num=1){

if(!$this->hasItem($id)){

return false;

}

$this->items[$id][‘num‘] = $num;

}

/*商品数量增加1*/

publicfunctionincNum($id,$num =1){

if($this->hasItem($id)){

$this->items[$id][‘num‘] +=1;

}

}

/*商品数量减少1*/

publicfunctiondecNum($id,$num =1){

if($this->hasItem($id)){

$this->items[$id][‘num‘]  -=$num;

}

/*如果数量减到0 就应该从购物车删除*/

if($this->items[$id][num]<1){

$this->delItem($id);

}

}

/*删除商品*/

publicfunctiondelItem($id){

unset($this->items[$id]);

}

/*查询购物车中商品的种类*/

publicfunctiongetCnt(){

return count($this->items);

}

/*查询购物车中商品的个数*/

publicfunctiongetNum(){

if($this->getCnt() == 0 ){

return 0;

}

$sum = 0;

foreach($this->items as $item){

$sum += $item[‘num‘];

}

return $sum;

}

/*查询购物车中商品的总金额*/

publicfunctiongetPrice(){

if($this->getCnt() == 0){

return 0;

}

$price = 0.0;

foreach($this->items as $item){

$price +=  $item[‘num‘]*$item[‘price‘];

}

return $price;

}

/*返回购物车中的所有商品*/

publicfunctiongetAll(){

return $this->items;

}

}

/*测试单例模式*/

//print_r(CartTool::getCart());

//测试添加购物车，清空购物车

/* $cart = CartTool::getCart();

if($_GET[‘test‘] == ‘add‘){

$cart->addItem(1,‘apple‘,23,3);

$cart->addItem(32,‘egg‘,54.7,1);

$cart->addItem(5,‘water‘,34.1,4);

echo "add ok";

}else if($_GET[‘test‘] == ‘clear‘){

$cart->clear();

}else if($_GET[‘test‘] == ‘show‘){

print_r($cart->getAll());

echo ‘<br/>‘;

echo "共".$cart->getCnt()."种商品".$cart->getNum().‘个‘;

echo ‘共‘.$cart->getPrice().‘元‘;

}else{

print_r($cart);

}*/