Iterated Object ( Symbol.iterator )

iterated.object.js

const collection = {
  a: 10,
  b: 20,
  c: 30,
  [Symbol.iterator]: function * () {
    for (let key in this) {
      yield this[key];
    }
  }
};

const iterator = collection[Symbol.iterator]();
  
console.log(iterator.next());    // → {value: 10, done: false}
console.log(iterator.next());    // → {value: 20, done: false}
console.log(iterator.next());    // → {value: 30, done: false}
console.log(iterator.next());    // → {value: undefined, done: true}