ES6 生成器和迭代器

Question

迭代器

let obj = {
  0: 1,
  1: 2,
  2: 3,
  length: 3,
  [Symbol.iterator] () {
    let that = this;
    let len = 0;
    return {
      next () {
        return {done: len === that.length, value: that[len++]}
      }
    }
  }
}

for (const i of obj) {
  console.log(i)
}

生成器

let obj = {
  0: 1,
  1: 2,
  2: 3,
  length: 3,
  [Symbol.iterator]: function * gen () {
    let len = 0
    while (len < this.length) {
      yield this[len++]
    }
  }
}

for (const i of obj) {
  console.log(i)
}