php - 如何在 PHP 中使用另一个数组对数组进行计数？

Question

我有一个群组数组和一个成员数组。 Group_one 可以是 Member、Admin 等

//groups:
Array
(
[0] => Array
    (
        [id] => 1
        ...
        [name] => Group_one
        ...
    )
[1] => Array
    (
        [id] => 2
        ...
        [name] => Group_two
        ... 
    )
...

---

//members:
CI_DB_mysql_result Object
(
[conn_id] => Resource id #12
[result_id] => Resource id #55
[result_array] => Array
    (
        [0] => Array
            (
                [id] => 2
                ...
                [group] => Group_2
                [group_id] => 2

            )
        [1] => Array
            (
                [id] => 5
                ...
                [group] => Group_four
                [group_id] => 4

            )
            ...

现在我想统计 Group_one、Group_two 等中有多少

我尝试了以下但没有用。

foreach($groups as $group)
{
  foreach ($members->result_array() as $key => $list)
  {
    if($group['id']==$list['group_id'])
    {   
        $stack[] = array();
        array_push($stack,$list);
    }
  }
}
echo "<pre>stack is:";
//print_r($stack);
echo count($stack);
echo"</pre>end of stack";

Answer 1

像这样的事情怎么样 -

$groupCount = array();
foreach($groups as $group){ $groupCount[$group['id']] = 0; }
foreach($members->result_array() as $member){
  $groupCount[$member['group_id']]++;
}

print_r($groupCount);

1. 首先，我创建并初始化了一个数组，以保存组的每个 group_id 的所有总数。
2. 然后我遍历每个成员并通过成员的group_id参数增加该组的计数器。