Testing the numbers for the Monty Hall, Goat Behind Door Problem

gistfile1.php

<?php

function selectDoorPrizeIsBehind(){
	return rand(1,3);
}
function selectDoorToOpen(){
	return rand(1,3);
}

/**
 * Off the none-prize doors, reveal a goat behind it.
 * @param $prizeDoor
 *
 * @return int
 */
function revealGoat($prizeDoor,$doorToOpen){
	$allDoors = array(
		1 => 1,
		2 => 2,
		3 => 3
	);
	unset($allDoors[$prizeDoor]); // Don't reveal the prize door
	if($prizeDoor != $doorToOpen) {
		unset($allDoors[$doorToOpen]);
	} // Don't show behind the selected door either (If it's a different door to the prize door)

	return $allDoors[array_rand($allDoors)];
}

/**
 * When we stick, then if the two doors match, we win.
 * @param $prizeDoor
 * @param $doorToOpen
 *
 * @return bool
 */
function stickWithDoor($prizeDoor,$doorToOpen){
	if($prizeDoor == $doorToOpen){
		return true;
	} else {
		return false;
	}
}

/**
 * In this case, we do the opposite
 * @param $prizeDoor
 * @param $doorToOpen
 *
 * @return bool
 */
function openOtherDoor($prizeDoor,$doorToOpen){
	if($prizeDoor == $doorToOpen){
		return false;
	} else {
		return true;
	}
}

$c = 0;
$stickWins = 0;
$changeWins = 0;
while($c < 1000000){
	$prizeDoor = selectDoorPrizeIsBehind();
	//echo 'Prize is behind door: ' . $prizeDoor;
	$doorToOpen = selectDoorToOpen();
	//echo ' Picking door: ' . $doorToOpen;
	$theGoatIsBehind = revealGoat($prizeDoor,$doorToOpen);
	//echo ' Revaling a goat behind door: ' . $theGoatIsBehind;
	if(stickWithDoor($prizeDoor,$doorToOpen)){
	//	echo ' Sticking You Win ';
		$stickWins++;
	}
	if(openOtherDoor($prizeDoor,$doorToOpen)) {
	//	echo ' Changing You Win ';
		$changeWins++;
	}
	//echo "\n";
	++$c;
}

echo 'Out of '.$c.' games, sticking you win ' . $stickWins . ' but changing you win ' . $changeWins .' times.';