Sorting array for every child coming after parent

Question

I have an array like that:

 1,
        \'parent_id\' => null
    ),
    array(
        \'id\' => 2,
             


        

Answer 1

Working solution : PHP has user define sorting function uasort I have used this to sort your array.

 1,
        'parent_id' => null
    ),
    array(
        'id' => 2,
        'parent_id' => 1
    ),
    array(
        'id' => 3,
        'parent_id' => null
    ),
    array(
        'id' => 4,
        'parent_id' => 2
    )
);



function cmp($a, $b) {    
    if ($a['parent_id'] == $b['parent_id']) {
        return 0;
    }
    return ($a['parent_id'] < $b['parent_id']) ? -1 : 1;
}

uasort($data, 'cmp');
echo '
';
print_r($data);
echo '
';