Test: tail recurison

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

View test history (8) Run this test again Return to test menu

Result: Discarded

The test labeled "normal recursion" was the faster by 0.0406 seconds, (5.772% faster)

normal recursion 100%

tail recursion 94.228%

The normal recursion test took 0.6628 seconds.
The tail recursion test took 0.7034 seconds.

Nitty-Gritty

Each test case ran 20 random code order iterations consisting of 128,364 loops for a total of 2,567,280 runs.

Line execution difference (0.000016) milliseconds.
Avg difference (2.030) milliseconds per 128,364 loops.
Total difference 40.59 milliseconds for 2,567,280 loops

The iteration variablity for Code 1 was (5.2907) milliseconds and Code 2 was (5.6489) 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, '');

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