How to get root path using "." and ".."?

Question

PHP

How to get path back to root? For example
https://example.com/test/another_test/index.php
, you need to get the path to
https://example.com/
. In this case, the path should look like:
/../../

How to do this?

Answer 1

Why not just use /?
../is a relative path.
/- absolute