text: //@target: ES5
  var array = [
      1,
      2,
      3
  ];
  var sum = 0;
  var _iteratorNormalCompletion = true, _didIteratorError = false, _iteratorError = undefined;
  try {
      for(var _iterator = array[Symbol.iterator](), _step; !(_iteratorNormalCompletion = (_step = _iterator.next()).done); _iteratorNormalCompletion = true){
          var num = _step.value;
          if (sum === 0) {
              array = [
                  4,
                  5,
                  6
              ];
          }
          sum += num;
      }
  } catch (err) {
      _didIteratorError = true;
      _iteratorError = err;
  } finally{
      try {
          if (!_iteratorNormalCompletion && _iterator.return != null) {
              _iterator.return();
          }
      } finally{
          if (_didIteratorError) {
              throw _iteratorError;
          }
      }
  }
  