Online PHP editor | refs for sP9s0

<?php $array = [ 'a', 'b', 'c', ]; function insertWhileIteratingForward($arr) { foreach ($arr as $index => $value) { if ($value === 'a' || $value === 'c') { array_splice($arr, $index, 0, ['new', 'new', 'new', 'new', 'new']); } } return $arr; } function insertWhileIteratingBackward($arr) { for ($index = count($arr) - 1; $index >= 0; --$index) { $value = $arr[$index]; if ($value === 'a' || $value === 'c') { array_splice($arr, $index, 0, ['new', 'new', 'new', 'new', 'new']); } } return $arr; } var_dump(insertWhileIteratingForward($array)); var_dump(insertWhileIteratingBackward($array));