This function will extract the file extension from a string that represents a filename. It retrieves the characters after the last dot and returns them as a new string.

1. function GetExt($Filename)
2. {
3.         $Extension = explode(".", $Filename);
4.         $Extension_i = (count($Extension) - 1);
5.         return $Extension[$Extension_i];
6. }
7.  
8. // How to use it
9. $Extension = GetExt("Lost.wmv");