Regex

1.js

var link = 'http://www.google.com/uploads/art/art_max_156575641388.0.png'

var parsingUrl = link.match(/\.([^.]*?)(?=\?|#|$)/)
/* [ '.png', 'png', index: 56, input: 'http://www.google.com/uploads/art/art_max_156575641388.0.png', groups: undefined ] */

var isPath = (/\.(jpg|jpeg|png)$/i).test(link)
/* true */


trimmedArtist = artist
          .trim()
          .replace(/[^a-zA-Z0-9]+/g, " ") // remove special characters
          .replace(/[ \t]+$/g, "") // remove trailing whitespace
          .replace(/\s+/g, "_"); // replace whitespace to '_'