URL Parser using Javascript

urlify.js

function urlify(input) {
  var regex = /(https?:\/\/[^\s]+)/g;
  return input.replace(regex, function (url){
    // Whitelist for last character of URL (Accept other than Letters, numbers and underscore)
    var lastCharRegex = /[^\w]$/; 
    var lastChar = '';

    // Check if URL ends with and special characters (such as , . - ! ? etc)
    if(lastCharRegex.test(url)) {

      // Check if last special character is either #, ? or / if it is then replace it with empty space 
      // as these characters hold no meaning in URL
      lastChar = url[url.length-1].replace(/['#', '?', '\/']/, '');

      // Trim special character from URL occured on last position
      url = url.replace(lastCharRegex, '');
    }

    return '<a "href="' + url + '">'+ url + '</a>' + lastChar;
  });
}