Example of php calculating the execution time of the current page

//do something
sleep(3);
//do something
$running_time = time() - $_SERVER['REQUEST_TIME'];
echo 'Page running time:', $running_time,' seconds';
?>

Execution example output is as follows: Page running time: 3 seconds annotation: $_SERVER['REQUEST_TIME'] is PHP's built-in timestamp when the current page starts running. When the current page ends, time() - $_SERVER['REQUEST_TIME'] will get the time (seconds) when the current page runs.