PHP multi-dimensional array being added too

having an issue with something. I have an array called result which is in the following format:

Array
(
    [count] => 74
    [0] => Array 
    (
        [15] => usncreated
        [memberof] => Array
        (
            [count] => 3
            [0] => GroupA
            [1] => GroupB
            [2] => GroupC
        )

    )
    [1] => Array 
    (
        [15] => usncreated
        [memberof] => Array
        (
            [count] => 2
            [0] => GroupA
            [1] => GroupF
        )

    )
)

I am trying to build up my own array now. At the moment I have

foreach($result as $user) {

    if(isset($user["memberof"])){
        foreach($user["memberof"] as $group) {
            $groups[] = $group;
        }

     }
     $userData["group"] = $groups;

     print_r("<pre>");
        print_r($userData);
     print_r("</pre>");
 }

Problem is my output is like so

Array
(
    [group] => Array
    (
        [0] => 2
        [1] => GroupA
        [2] => GroupB
    )
)

Array
(
    [group] => Array
    (
        [0] => 2
        [1] => GroupA
        [2] => GroupB
        [3] => 2
        [4] => GroupA
        [5] => GroupF
    )
)

So the second one repeats the first. If I move the print_r somewhere else, like outside the loop, I just see one user with every possible group. I know it needs to print in a loop, but whatever I try I cant get the correct output.

How can I get it to only display the groups for each user?

Thanks