PHP如何删除最后一个斜杠之间的子串？

Here is my string:

test-e2e4/folder1/folder2/6.png.

I want to remove the last part of it, so it should look like this:

test-e2e4/folder1/folder2/

How can i do that using preg_replace() ?

$string = preg_replace('#[^/]*$#', '', $string);

DEMO.

besides preg_replace, you can also use dirname

echo dirname("test-e2e4/folder1/folder2/6.png") . "/";