我有一个$cart数组（），它是发布到数据库之前的会话变量。
array (size=2)
1 =>
array (size=5)
'id' => string '1' (length=1)
'price' => string '10' (length=2)
'qty' => int 2
'item_desc' => string 'Fast Food 01' (length=12)
'special_desc' => string '' (length=0)
'1S' =>
array (size=5)
'id' => string '1' (length=2)
'price' => string '10' (length=2)
'qty' => string '1' (length=1)
'item_desc' => string 'Fast Food 01' (length=12)
'special_desc' => string 'Special Cook style 1' (length=3)
举个例子，项id是"1"，但为了避免重复键的冲突，我放了"S"来表示它是一个有特殊描述的数组元素。
这是我当前的编码
...
if (array_key_exists($item_id, $cart)) {
$key_item_id = $item_id . 'S';
}
$cart[$key_item_id] = array('id' => $item_id, 'price' => $price, 'qty' => $qty, 'item_desc' => $item_desc, 'special_desc' => $special_desc);
...
然而，可能有不止一个特殊描述，所以我认为它应该在和"S"之后有一个计数器编号，例如"1S1"，以特殊描述样式1表示项目id"1"，用特殊描述样式2表示"1S2"，依此类推
array (size=2)
1 =>
array (size=5)
'id' => string '1' (length=1)
'price' => string '10' (length=2)
'qty' => int 2
'item_desc' => string 'Fast Food 01' (length=12)
'special_desc' => string '' (length=0)
'1S1' =>
array (size=5)
'id' => string '1' (length=2)
'price' => string '10' (length=2)
'qty' => string '1' (length=1)
'item_desc' => string 'Fast Food 01' (length=12)
'special_desc' => string 'Special Cook style 1' (length=3)
'1S2' =>
array (size=5)
'id' => string '1' (length=2)
'price' => string '10' (length=2)
'qty' => string '1' (length=1)
'item_desc' => string 'Fast Food 01' (length=12)
'special_desc' => string 'Special Cook style 2' (length=3)
我的问题是如何"计数"有多少物品id为"1"的$cart，以便我可以实现它的当前计数器？
谢谢。
使用键不是个好主意。我认为应该用一个键将same ID的所有项存储在数组项中。
1 =>
array (size=4)
'price' => string '10' (length=2)
'qty' => int 2
'item_desc' => string 'Fast Food 01' (length=12)
'special_desc' => string '' (length=0)
array (size=4)
'price' => string '10' (length=2)
'qty' => string '1' (length=1)
'item_desc' => string 'Fast Food 01' (length=12)
'special_desc' => string 'Special Cook style 1' (length=3)
array (size=4)
'price' => string '10' (length=2)
'qty' => string '1' (length=1)
'item_desc' => string 'Fast Food 01' (length=12)
'special_desc' => string 'Special Cook style 2' (length=3)`
更进一步，您可以添加密钥total_quantity和special_items_quantity，并在向数组添加新项目时增加/减少它们：
1 =>
total_quantity => 4 // now it is 4
special_items_quantity => 2 // now it is 2
array (size=4)
'price' => string '10' (length=2)
'qty' => int 2
'item_desc' => string 'Fast Food 01' (length=12)
'special_desc' => string '' (length=0)
array (size=4)
'price' => string '10' (length=2)
'qty' => string '1' (length=1)
'item_desc' => string 'Fast Food 01' (length=12)
'special_desc' => string 'Special Cook style 1' (length=3)
array (size=4)
'price' => string '10' (length=2)
'qty' => string '1' (length=1)
'item_desc' => string 'Fast Food 01' (length=12)
'special_desc' => string 'Special Cook style 2' (length=3)`
通过将$index的值设置为您的产品id，$cnt将获得该产品的正常和特殊订单的总量：
$index = 1;
$cnt = array('total' => 0, 'normal' => 0, 'special' => 0);
array_walk($arr, function ($i, $k) use(&$cnt, $index){
if ($i['id'] == $index){
$cnt['total'] += $i['qty'];
if ((string)$k == (string)$index) $cnt['normal'] += $i['qty'];
else $cnt['special'] += $i['qty'];
}
});
print_r($cnt);
注意：此解决方案需要PHP 5.3或更高版本。
哇，那复杂的东西什么都没有。。。。你应该用另一种方法。。。
另外，你也可以试试这样的东西：
$count = 0;
foreach($cart as $item){
if(!empty($item['special_desc'])) $count++;
}
// count is the number of special_desc in the $cart array...