php新手购物车实现的原理

//加入购物车 function addcart($goods_id,$goods_num){ $cur_cart_array = unserialize(stripslashes($_COOKIE['shop_cart_info'])); if($cur_cart_array==""){ $cart_info[0][] = $goods_id; $cart_info[0][] = $goods_num; setcookie("shop_cart_info",serialize($cart_info)); }elseif($cur_cart_array<>""){ //返回数组键名倒序取最大 $ar_keys = array_keys($cur_cart_array); rsort($ar_keys); $max_array_keyid = $ar_keys[0]+1; //遍历当前的购物车数组 //遍历每个商品信息数组的0值，如果键值为0且货号相同则购物车存在相同货品 foreach($cur_cart_array as $goods_current_cart){ foreach($goods_current_cart as $key=>$goods_current_id){ if($key == 0 and $goods_current_id == $goods_id){ echo ""; exit(); } } } $cur_cart_array[$max_array_keyid][] = $goods_id; $cur_cart_array[$max_array_keyid][] = $goods_num; setcookie("shop_cart_info",serialize($cur_cart_array)); } } //从购物车删除 function delcart($goods_array_id){ $cur_goods_array = unserialize(stripslashes($_COOKIE['shop_cart_info'])); //删除该商品在数组中的位置 unset($cur_goods_array[$goods_array_id]); setcookie("shop_cart_info",serialize($cur_goods_array)); } //修改购物车货品数量 function update_cart($up_id,$up_num,$goods_ids){ //先清空cookie,以便重新设置，传递过来三个数组参数 1数组的标识 2商品数量数组 3商品编号数组 //如果不清空cookie则无法处理数量为零的商品 setcookie("shop_cart_info",""); foreach($up_id as $song){ //先返回数组当前单元；再把指针向下移动一个位置 $goods_nums = current($up_num); $goods_id = current($goods_ids); next($up_num); next($goods_ids); //当商品数量为空的时候，注销此处的数组值并用continue 2 语句避开下面的操作，继续做foreach循环 while($goods_nums == 0){ unset($song); continue 2; } $cur_goods_array[$song][0] = $goods_id; $cur_goods_array[$song][1] = $goods_nums; } setcookie("shop_cart_info",serialize($cur_goods_array));