How to count in array by using another array in PHP
<p>I have a groups array and members array. Group_one can be Member, Admin etc</p>

<pre><code>//groups:
Array
(
[0] =&gt; Array
    (
        [id] =&gt; 1
        ...
        [name] =&gt; Group_one
        ...
    )
[1] =&gt; Array
    (
        [id] =&gt; 2
        ...
        [name] =&gt; Group_two
        ... 
    )
...
</code></pre>

<hr>

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

            )
        [1] =&gt; Array
            (
                [id] =&gt; 5
                ...
                [group] =&gt; Group_four
                [group_id] =&gt; 4

            )
            ...
</code></pre>

<p>Now I want to count how many in Group_one, Group_two etc.</p>

<p>I tried the following but not working.</p>

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

<p>I appreciate any help.</p>

<p>Thanks in advance.</p>
