Something

<?php$flip = array('even' => 'odd', 'odd' => 'even');$class = 'even';$time_start = microtime(true);for ($number = 0; $number < 100000; $number++) {  $class = ($number % 2 == 1) ? 'even': 'odd';}$time_end = microtime(true);$old_time = $time_end - $time_start;$time_start = microtime(true);for ($number = 0; $number < 100000; $number++) {  $class = $flip[$class];}$time_end = microtime(true);$new_time = $time_end - $time_start;echo "Old time is $old_time seconds\n";echo "New time is $new_time seconds\n";?>// ResultOld time is -0.272475 secondsNew time is -0.420923 seconds