Convert numbers to ordinal form. ie) 1,2,3,4,...N to '1st', '2nd', '3rd', '4th',...'Nth'

ordinal.js

/* ordinal(n)
 * @param {number} n - the number to output an ordinal for.
 * Convert numbers to ordinal form. ie) 1,2,3,4,...N to '1st', '2nd', '3rd', '4th',...'Nth'
 */
ordinal = function(n) {
  if (n === 1) {
    n += 'st';
  } else if (n === 2) {
    n += 'nd';
  } else if (n === 3) {
    n += 'rd';
  } else {
    n += 'th';
  }
  return n;
};