Test: tail recurison

Is using tail-end recursion (where the recursion happens at the end of the function) any better?

View test history (3) Run this test again Return to test menu

Result: Saved

The test labeled "tail recursion" was the faster by 0.1508 seconds, (8.496% faster)

tail recursion 100%

normal recursion 91.504%

The tail recursion test took 1.6243 seconds.
The normal recursion test took 1.7751 seconds.

Nitty-Gritty

Each test case ran 20 random code order iterations consisting of 278,506 loops for a total of 5,570,120 runs.

Line execution difference (0.000027) milliseconds.
Avg difference (7.540) milliseconds per 278,506 loops.
Total difference 150.80 milliseconds for 5,570,120 loops

The iteration variablity for Code 1 was (26.4184) milliseconds and Code 2 was (26.3798) milliseconds. The lower and the closer together there values are the more accurate the results are.

Code

The first test, "normal recursion", was:

/*
function recurse_tail($i, $inside)
{
	$data = '<div>' . $inside . '</div>';

	if ($i <= 0)
		return $data;
	else
		return recurse_tail($i - 1, $data);
}
*/

$result = recurse_tail(200, '');

The second test, "tail recursion", was:

/*
function recurse_normal($i, $inside)
{
	$data = '<div>';
	if ($i <= 0)
		$data .= $inside;
	else
		$data .= recurse_normal($i - 1, $data);
	$data .= '</div>';

	return $data;
}
*/

$result = recurse_normal(200, '');

PHP Benchmarks