我想要一个来自多维数组的键的值数组

Question

I have an array structure like below

array
{
     [0]=>
     {
            [name] = "maulik";
            [roleId] = 34;
     }
     [1]=>
     {
            [name] = "ketan";
            [roleId] = 12;
     }
     [2]=>
     {
            [name] = "nitish";
            [roleId] = 40;
     }
     [3]=>
     {
            [name] = "hiren";
            [roleId] = 24;
     }
}

I want array of all roleId field by a single php function. Is there any php function available or I have to use like below?

$roleIds = array();
foreach($users as $user)
{
    $roleIds[] = $user['roleId'];
}

Solution for the visitors from search engine....

function getRoleIdsAsArray($index)
{
        return $index['roleId'];
}

$roleIds = array_map("getRoleIdsAsArray" , $users);

Answer 1

maybe this one is a solution suitable to you:

$roleIds = array_map(function($c) {return $c['roleId'];}, $users);

It use array_map, available since php 4 and anonymous functions introduced into php since version 5.2