php get filename with extension from path code example

Example: filename php

echo "1) ".basename("/etc/sudoers.d", ".d").PHP_EOL;//sudoers
echo "2) ".basename("/etc/sudoers.d").PHP_EOL;//sudoers.d
echo "3) ".basename("/etc/passwd").PHP_EOL;//passwd
echo "4) ".basename("/etc/").PHP_EOL;//etc
echo "5) ".basename(".").PHP_EOL;//.
echo "6) ".basename("/");//