basename in PHP

Syntax of basename

string basename(string path[, string suffix])

Returns the filename component from the full path path. If the file’s name ends in suffix, that string is removed from the name. For example:

$path = “/usr/local/httpd/index.html”;
echo(basename($path)); // index.html
echo(basename($path, ‘.html’));

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

1) sudoers
2) sudoers.d
3) passwd
4) etc
5) .
6)