Some ES6 that will make all objects directly iterable in a convenient but utterly unrecommended way.

so_naughty_but_so_sweet.js

Object.prototype[Symbol.iterator] = function() {
   iterator = {
      values: Object.keys(this).map((function (k) {
         return [k, this[k]];
      }).bind(this)),
      next: function() {
         if (this.values.length <= 0) {
            return {done: true};
         } else {
            return {value: this.values.shift(), done:false};
         }
      }
   }
   return iterator;
}

let o = {a:5, b:6, c:7};

for (let [k, v] of o) {
   console.log(`${k} is ${v}`);
}

// Output:
// a is 5
// b is 6
// c is 7

Implemented with the ugly values array so it could run in my browser. May as well use an actual generator though.