strtolower() vs strtoupper performance test

strtolower_vs_strtoupper_performance_test.php

<?php

$string = 'hello world';
$start_time = microtime();
for ($i = 0; $i < $max = 10000000; $i++) {
	strtolower($string);
}
$timed = microtime() - $start_time;
echo 'strtolower ' . $string . ' - ' . $timed . '<br>';

$string = 'hello world';
$start_time = microtime();
for ($i = 0; $i < $max = 10000000; $i++) {
	strtoupper($string);
}
$timed = microtime() - $start_time;
echo 'strtoupper ' . $string . ' - ' . $timed . '<br>';

$string = 'HELLO WORLD';
$start_time = microtime();
for ($i = 0; $i < $max = 10000000; $i++) {
	strtolower($string);
}
$timed = microtime() - $start_time;
echo 'strtolower ' . $string . ' - ' . $timed . '<br>';

$string = 'HELLO WORLD';
$start_time = microtime();
for ($i = 0; $i < $max = 10000000; $i++) {
	strtoupper($string);
}
$timed = microtime() - $start_time;
echo 'strtoupper ' . $string . ' - ' . $timed . '<br>';

$string = 'Hello World';
$start_time = microtime();
for ($i = 0; $i < $max = 10000000; $i++) {
	strtolower($string);
}
$timed = microtime() - $start_time;
echo 'strtolower ' . $string . ' - ' . $timed . '<br>';

$string = 'Hello World';
$start_time = microtime();
for ($i = 0; $i < $max = 10000000; $i++) {
	strtoupper($string);
}
$timed = microtime() - $start_time;
echo 'strtoupper ' . $string . ' - ' . $timed . '<br>';