code: function fromQueryStringWithOptions(obj, opts) {
    var str = String(obj || '').replace(/^.*?\?/, ''), result = {}, auto;
    opts = opts || {};
    if (str) {
      forEach(str.split('&'), function(p) {
        var split = p.split('=');
        var key = decodeURIComponent(split[0]);
        var val = split.length === 2 ? decodeURIComponent(split[1]) : '';
        auto = opts.auto !== false;
        parseQueryComponent(result, key, val, opts.deep, auto, opts.separator, opts.transform);
      });
    }
    return result;
  }
docs: Query Strings | Parsing