HTML, CSS and JavaScript demo

var totalItems, sum, type, value;
totalItems = [];
totalItems[0] = 3;
totalItems[1] = 2;
totalItems.__ob__ = new Object();
Object.defineProperty(totalItems, '__ob__', {
    enumerable: false,
    writable: true,
    configurable: true
  });
sum = 0;
for (type in totalItems) {
  value = totalItems[type];
  sum += value;
}
document.getElementById('forin').innerHTML = sum;

sum = 0;
totalItems.forEach(function(item) {
  sum += item;
});
document.getElementById('foreach').innerHTML = sum;

sum = 0;
sum = totalItems.reduce(function(t, s) {
  return t + s;
});
document.getElementById('reduce').innerHTML = sum;

sum = 0;
var foo = totalItems;
// From https://babeljs.io/docs/en/babel-plugin-transform-for-of
var _iteratorNormalCompletion = true;
var _didIteratorError = false;
var _iteratorError = undefined;

try {
  for (var _iterator = foo[Symbol.iterator](), _step; !(_iteratorNormalCompletion = (_step = _iterator.next()).done); _iteratorNormalCompletion = true) {
    var i = _step.value;
    sum += _step.value;
  }
} catch (err) {
  _didIteratorError = true;
  _iteratorError = err;
} finally {
  try {
    if (!_iteratorNormalCompletion && _iterator.return != null) {
      _iterator.return();
    }
  } finally {
    if (_didIteratorError) {
      throw _iteratorError;
    }
  }
}
document.getElementById('forofbabel').innerHTML = sum;