Online PHP editor | refs for uTsbl

<?php $count = 100; $start = microtime(true); for ($i = 0; $i < $count; $i++) { $str = "abc"; $str = preg_replace_callback('/a/', 'strtoupper', $str); $str = preg_replace_callback('/b/', 'strtoupper', $str); $str = preg_replace_callback('/c/', 'strtoupper', $str); $str = preg_replace_callback('/a/', 'strtolower', $str); $str = preg_replace_callback('/b/', 'strtolower', $str); $str = preg_replace_callback('/c/', 'strtolower', $str); } echo "Completed in " . (microtime(true) - $start) . " Seconds\n"; $start = microtime(true); for ($i = 0; $i < $count; $i++) { $str = "abc"; $str = preg_replace(array( '/a/e', '/b/e', '/c/e', '/a/e', '/b/e', '/c/e', ), array( 'strtoupper(\'$1\')', 'strtoupper(\'$1\')', 'strtoupper(\'$1\')', 'strtolower(\'$1\')', 'strtolower(\'$1\')', 'strtolower(\'$1\')', ), $str ); } echo "Completed in " . (microtime(true) - $start) . " Seconds\n";