SOURCE

// 对Object进行原型编程
  Object.prototype[Symbol.iterator] = function* () {
    let index = 0;
    let arr = Object.entries(this);
    let length = arr.length;
    while (true) {
      if (index >= length) {
        return false
      } else {
        let key = arr[index] && arr[index][0];
        let text = arr[index] && arr[index][1];
        let value = { [key]: text };
        index++;
        yield value
      }
    }
  };
 
  // 测试
  const myObj = {
    a: 1,
    b: 2,
    c: 3,
  }
  for (const [item] of myObj) {
    console.log(item);
  }
/*
  输出：
  {a: 1}
  {b: 2}
  {c: 3}
  
  */