create a hole in an array

Question

I have an array of the form

$array = array(1 => 'a',
               2 => 'b',
               3 => 'c',
               4 => 'd')

and I would like to create a 'hole' between 2 and 3, i.e. obtain the following array

$array = array(1 => 'a',
               2 => 'b',
               4 => 'c',
               5 => 'd')

What do you reckon to be the best way to do this?

Answer 1

This should work:

function array_drill_hole($input, $start, $end) {
    array_splice($input, $start, $end - $start, null);
    return $input;
}

Answer 2

$array = array_combine(array_merge(range(1, 2), range(4, 5)), $array);