Re: while-question

Stut wrote:

On 17 Nov 2008, at 14:31, Nathan Rixham wrote:

if you really want a challenge try this one.. task: add the numbers 5 and 17 together, using php, without using the + operator. fill it in: function add($a , $b) { //code here but no + - / * operators return $answer; } echo add(5, 17);

Elemental my dear Mr Rixham... function add($a , $b) { $answer = $a ^ $b; while (0 != ($a & $b)) {

    $b = ($a & $b) << 1;
    $answer = $answer ^ $b;

} return $answer; } -Stut

what an answer; very nice and indeed full marks mr stut! now then.. echo add(5,17) . ' ' . (5 + 17) . PHP_EOL; echo add(-5,17) . ' ' . (-5 + 17) . PHP_EOL; echo add(5,-17) . ' ' . (5 + -17) . PHP_EOL; echo add(-5,-17) . ' ' . (-5 + -17) . PHP_EOL; (can you tell I've been down this route before?)