/*
Description:
Are you a file extension master? Let's find out by checking if Bill's files are images or audio files. Please use regex if available natively for your language.

You will create 2 string methods:

isAudio/is_audio, matching 1 or + uppercase/lowercase letter(s) (combination possible), with the extension .mp3, .flac, .alac, or .aac.

isImage/is_image, matching 1 or + uppercase/lowercase letter(s) (combination possible), with the extension .jpg, .jpeg, .png, .bmp, or .gif.

Note that this is not a generic image/audio files checker. It's meant to be a test for Bill's files only. Bill doesn't like punctuation. He doesn't like numbers, neither. Thus, his filenames are letter-only

Rules

It should return true or false, simply.
File extensions should consist of lowercase letters and numbers only.
File names should consist of letters only (uppercase, lowercase, or both)
*/
String.prototype.isAudio= function(){
  return /\.mp3|\.flac|\.alac|\.aac/.test(this)&&!/[\s]/.test(this)
};
String.prototype.isImage= function(){
  return /\.jpg|\.jpeg|\.png|\.bmp|\.gif/.test(this)&&!/[\s]/.test(this)&&!/[\d]/g.test(this)
};
