为什么我的QUERY_STRING为空？

I am running a server locally. It's Apache2 with PHP. Following are the files that I have written.

.htaccess

ErrorDocument 404 /notFoundError.php

/notFoundError.php

<?php
  echo phpinfo();
?>

When I type some non-existing url http://localhost/this/is/dummy?key=value, it successfully redirects to notFoundError.php and prints the phpinfo table. There I do not find key=value in the _SERVER["QUERY_STRING"] row.

Check out how to Pass query string in 404 error redirect through .htaccess? for your answer.

You will need to access $_SERVER['REDIRECT_QUERY_STRING']

If you are sending to a page which does not exist, a 404 will be invoked. Which is why you are being redirect to notFoundError.php and then displaying its contents?

What are you trying to accomplish?