gistfile1.php

<?php

$input = ['a' => 'b', 'c' => 'd'];
$keys = array_keys($input);
$values = array_values($input);
$i = 0;

while (isset($keys[$i], $values[$i])) {
	$currentKey = $keys[$i];
	$currentValue = $values[$i];
	// Do whatever you want

	++$i
}