为什么PHP重定向在实际重定向之前加载页面？

Question

I have a page that takes a few seconds to load, and a login check / redirect set up using PHP header("Location:"). When visiting the page as a logged out user, I noticed that it takes a few seconds before actually redirecting to the login page, and assume that it is rendering the full code of the page first. But since the redirect needs to render before anything else, why does it continue to execute the remainder of the pages code?

Answer 1

you should have exit() right after the header() location call to stop any of the rest of the page processing.

example from the manual

<?php
header("Location: http://www.example.com/"); /* Redirect browser */

/* Make sure that code below does not get executed when we redirect. */
exit;
?>