How to include() all PHP files from a directory ?

 Example - 

This example contains four PHP files (test1.php, test2.php, test3.php, test4.php) in a directory. Create one file named as include.php which contains PHP code to include files.

Create include.php outside folder:  

<?php
foreach (glob("folder/*.php") as $filename) {
	include $filename;
}
?>