// source http://jsbin.com/gist

<script src="https://static.jsbin.com/js/vendor/traceur.js"></script>

<script id="jsbin-javascript">

"use strict";

​

var s = new Set();

​

[2, 3, 5, 4, 5, 2, 2].forEach(function (x) {

  return s.add(x);

});

​

var _iteratorNormalCompletion = true;

var _didIteratorError = false;

var _iteratorError = undefined;

​

try {

  for (var _iterator = s[Symbol.iterator](), _step; !(_iteratorNormalCompletion = (_step = _iterator.next()).done); _iteratorNormalCompletion = true) {

    var i = _step.value;

​

    console.log(i);

  }

} catch (err) {

  _didIteratorError = true;

  _iteratorError = err;

} finally {

  try {

    if (!_iteratorNormalCompletion && _iterator["return"]) {

      _iterator["return"]();

    }

  } finally {

    if (_didIteratorError) {

      throw _iteratorError;

    }

  }

}

</script>

​

​

<script id="jsbin-source-javascript" type="text/javascript">const s = new Set();

​

[2, 3, 5, 4, 5, 2, 2].forEach(x => s.add(x));

​

for (let i of s) {

  console.log(i);

}</script>