original_string: public static function ext($fileName)
      {
          if (strpos($fileName, '.') === false) {
              return '';
          }
  
          return strtolower(
              substr(
                  $fileName,
                  strrpos($fileName, '.') + 1,
                  strlen($fileName)
              )
          );
      }
code: public static function ext($fileName)
      {
          if (strpos($fileName, '.') === false) {
              return '';
          }
  
          return strtolower(
              substr(
                  $fileName,
                  strrpos($fileName, '.') + 1,
                  strlen($fileName)
              )
          );
      }
code_tokens: public static function ext ( $ fileName ) { if ( strpos ( $ fileName , '.' ) === false ) { return '' ; } return strtolower ( substr ( $ fileName , strrpos ( $ fileName , '.' ) + 1 , strlen ( $ fileName ) ) ) ; }
docstring: Get file extension.
  
  @param string $fileName File name, including its extension. e.g.: `my-file.docx`
  @return string File extension without the ending DOT and lowercased,
  e.g. `pdf`, `jpg`, `png`, etc. If no extension is found an empty string will
  be returned
docstring_tokens: Get file extension .