Compare runtime of PHP functions

benchmark.php

<?php
	function benchmark(Callable $fn, ...$args) {
		$start = microtime(true);
		
		for ($i = 0; $i <= 23005; $i++) {
			$fn(...$args);
		}
		
		$end = microtime(true);
		$diff = ($end - $start);
		
		return round($diff, 6);
	}
	
	var_dump(
		
		benchmark(function() {
			$str = str_repeat('0', 36);
		}),
		
		benchmark(function() {
			$str = str_pad('', 36, '0', STR_PAD_LEFT);
		}),
		
		benchmark(function() {
			$str = str_pad('', 36, '0', STR_PAD_RIGHT);
		})
		
	);
?>