How to sort a multi dimensional array in PHP alphabetically?

Question

My API written in PHP (Codeigniter) outputs users based on a selected keyword how can I sort this array in alphabetical order before it outputs to JSON.

This is the outp

Answer 1

This one works. Tried, tested, and true:

function sort_by_lastname($a, $b) {
    $a = trim($a['user']['basic'][0]['lastname']);
    $b = trim($b['user']['basic'][0]['lastname']);
    return strcmp($a,$b);
}

uasort($array['contacts'],'sort_by_lastname');