如何将对象的对象转换为对象数组的对象js答案

【问题标题】：how to transform object of objects to object of array of objects js如何将对象的对象转换为对象数组的对象js
【发布时间】：2020-07-08 21:46:22
【问题描述】：

我目前正在处理一个包含日历屏幕的react-native 项目。我为日历本身使用react-native calendars 议程组件，为项目本身使用firebase 实时数据库。我在创建自己的数据库方面非常陌生，因此难以让我们的数据结构正确。目前，我从数据库中获取数据为

{
'2020-07-01': {time: "12:00", topic: "Type Casting in JavaScript"}
'2020-07-03': {time: "12:00", topic: "JavaScript basics"}
'2020-07-06': {time: "12:00", topic: "Parallax Scrolling"}
}

但其他本地日历议程仅接受以下形式的数据

{
'2020-07-01': [{time: "12:00", topic: "Type Casting in JavaScript"}]
'2020-07-03': [{time: "12:00", topic: "JavaScript basics"}]
'2020-07-06': [{time: "12:00", topic: "Parallax Scrolling"}]
}

转换输出的最佳方法是什么？

【问题讨论】：

标签： javascript firebase react-native firebase-realtime-database

【解决方案1】：

const OBJECT = {
'2020-07-01': {time: "12:00", topic: "Type Casting in JavaScript"},
'2020-07-03': {time: "12:00", topic: "JavaScript basics"},
'2020-07-06': {time: "12:00", topic: "Parallax Scrolling"},
};

console.log(
    Object.fromEntries(Object.entries(OBJECT).map(([key, val]) => [key, [val]]))
);

Here is working solution

【讨论】：

【解决方案2】：

const obj = {
'2020-07-01': {time: "12:00", topic: "Type Casting in JavaScript"},
'2020-07-03': {time: "12:00", topic: "JavaScript basics"},
'2020-07-06': {time: "12:00", topic: "Parallax Scrolling"}
}

const transformed = {};
for (const date in obj) {
  transformed[date] = [obj[date]]
}
console.log(transformed)

【讨论】：

【解决方案3】：

使用reduce：

const data = {
'2020-07-01': {time: "12:00", topic: "Type Casting in JavaScript"},
'2020-07-03': {time: "12:00", topic: "JavaScript basics"},
'2020-07-06': {time: "12:00", topic: "Parallax Scrolling"}
}

const normalized = Object.keys(data).reduce( (acc, key) => {
  acc[key] = [data[key]]
  
  return acc
}, {})

console.log(normalized)

【讨论】：

【解决方案4】：

编写一个函数将数据转换成你需要的结构。

const dataToTransform = {
'2020-07-01': {time: "12:00", topic: "Type Casting in JavaScript"},
'2020-07-03': {time: "12:00", topic: "JavaScript basics"},
'2020-07-06': {time: "12:00", topic: "Parallax Scrolling"}
}

const transformData = (input) => {
  const output = {} // object to return with transformed data
  Object.keys(input).forEach( key => {
    output[key] = [input[key]] // do whatever transformation here 
                               // for each key/value pair
  })
  return output
}

const transformedData = transformData(dataToTransform)

const pre = document.getElementById('display')
pre.textContent = JSON.stringify(transformedData)
console.log(transformedData)

<body>
<pre id='display'>
</pre>
</body>

注意有多种方法可以实现transformData。这只是一个例子。

【讨论】：