遍歷物件鍵值對的兩種方法

1、object.keys

for (var key of Object.keys(someObject)) {
  console.log(key + ': ' + someObject[key]);
}

2、使用 Generator 函式將物件重新包裝成陣列

function* entries(obj) {
  for (let key of Object.keys(obj)) {
    yield [key, obj[key]];
  }
}

for (let [key, value] of entries(obj)) {
  console.log(key, '->', value);
}