phpjs/functions/strings/strrchr.js

php.js offers community built php functions in javascript

function strrchr(haystack, needle) {
  //  discuss at: http://phpjs.org/functions/strrchr/
  // original by: Brett Zamir (http://brett-zamir.me)
  //    input by: Jason Wong (http://carrot.org/)
  // bugfixed by: Brett Zamir (http://brett-zamir.me)
  //   example 1: strrchr("Line 1\nLine 2\nLine 3", 10).substr(1)
  //   returns 1: 'Line 3'

  var pos = 0;

  if (typeof needle !== 'string') {
    needle = String.fromCharCode(parseInt(needle, 10));
  }
  needle = needle.charAt(0);
  pos = haystack.lastIndexOf(needle);
  if (pos === -1) {
    return false;
  }

  return haystack.substr(pos);
}