Online PHP editor | output for spdep

<?php $arr1 = array( 0 => 'number 1', 1 => 'number 2', 2 => 'number 3', 3 => 'number 4', 4 => 'number 5', ) ; $arr2 = array( 0 => 'number 4 insert', 1 => 'number 8 insert', 2 => 'number 12 insert', 3 => 'number 16 insert', 4 => 'number 24 insert', ) ; function match_arrayKeys ($x, $y,$z) { $keys = array_keys ($x); for ($i = 0; $i < count ($keys); $i++) { $j = $i+1; if($j%$z== 0 ){ $newarray [$i] = $y[$keys[$i]]; } else { $newarray [$i] = $x[$i]; } } return $newarray; } print_r (match_arrayKeys ($arr1,$arr2, 4));