for-of.js

// in helpers.js
Object.prototype.forOf = function(iterateFunc) {
  var keys = Object.keys(this),
      continueLoop = true;
  var breakLoop = () => continueLoop = false;
  for(var counter = 0; counter < keys.length && continueLoop; counter++) {
      iterateFunc(this, keys[counter], breakLoop);
  }
};

// for/of analog
myItems.forOf((items, key, breakLoop) => {
  if (items[key] === foo) {
    items[key] = "bar";
    breakLoop();
  }
});