code: function accessObject(obj, string) {
  
          var m, pos = 0;
          while ((m = string.substring(pos).match(accessExp))) {
  
              //         .name or       ["foo"] or [0]
              var prop = m[1] || (m[3] ? m[4] : +m[2]);
              if (obj === undefined) {
                  throw new FormatError(accessObject,
                                        'Cannot access property "{}" of undefined.',
                                        prop);
  
              } else {
                  obj = obj[prop];
              }
  
              pos += m[0].length;
  
          }
  
          return obj;
  
      }
docs: Resolve a string like "foo[0].bla['test']"