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使用JS创建一个新的包含新键的对象数组

javascriptarrays
3

我有两个JSON对象的数组：房间和预订。 我想输出一个新的对象数组，将这两个数组中的数据合并，并创建一种新的数据类型。 不确定如何创建该新数据类型。

var rooms = [
     {id:1, room:'treehouse'},
     {id:2, room:'casa'},
     {id:3, room:'vacation'},
     {id:4, room:'presidential'}
];

var reservations = [
  {id:1, roomID:'2', time:'2pm', location:'rome'},
  {id:2, roomID:'3', time:'4pm', location:'paris'},
  {id:3, roomID:'1', time:'4pm', location:'london'},
  {id:4, roomID:'2', time:'7pm', location:'rome'},
  {id:5, roomID:'1', time:'12pm', location:'london'},
  {id:6, roomID:'4', time:'4pm', location:'berlin'}
];

期望输出：

var bookings = [
  {id: 1, roomid:1, time:'12pm',location:'london', roomname:'treehouse'},
  {id: 2, roomid:1, time:'4pm', location:'london', roomname:'treehouse'},
  {id: 3, roomid:2, time:'2pm', location:'rome', roomname:'casa'},
  {id: 4, roomid:2, time:'7pm', location:'rome', roomname:'casa'},
  {id: 5, roomid:3, time:'4pm', location:'paris', roomname:'vacation'},
  {id: 6, roomid:4, time:'4pm', location:'berlin', roomname:'presidential'}
]

我对如何处理此事的逻辑感到困惑。我考虑遍历reservations数组，对于每个预订，获取roomId并在房间的映射结构中进行检查，然后输出。但我不太确定该怎么做。

这是不是意味着 roomid 和 roomID 有所区别？为什么类型不同，一个是数字，一个是字符串。 - Nina Scholz
6个回答
1

var rooms = [
     {id:1, room:'treehouse'},
     {id:2, room:'casa'},
     {id:3, room:'vacation'},
     {id:4, room:'presidential'}
];

var reservations = [
  {id:1, roomID:'2', time:'2pm', location:'rome'},
  {id:2, roomID:'3', time:'4pm', location:'paris'},
  {id:3, roomID:'1', time:'4pm', location:'london'},
  {id:4, roomID:'2', time:'7pm', location:'rome'},
  {id:5, roomID:'1', time:'12pm', location:'london'},
  {id:6, roomID:'4', time:'4pm', location:'berlin'}
];

console.log(
  reservations.map(a=>({...a, roomname: rooms.find(b=>b.id==a.roomID).room}))
)

0

你可以使用

reservations.map(function (val) {
    return Object.assign(val, rooms.find(function (item) {
        return val.roomID === item.id ? item : {}
    }))
})

如果这对你有用，请告诉我。

0
你可以使用Array.reduce()来创建一个带房间名称的 id 映射表，然后在预订上使用Array.map()将给定 id 的房间与房间名称合并： 

var rooms = [ {id:1, room:'treehouse'}, {id:2, room:'casa'}, {id:3, room:'vacation'}, {id:4, room:'presidential'} ];

var reservations = [ {id:1, roomID:'2', time:'2pm', location:'rome'}, {id:2, roomID:'3', time:'4pm', location:'paris'}, {id:3, roomID:'1', time:'4pm', location:'london'}, {id:4, roomID:'2', time:'7pm', location:'rome'}, {id:5, roomID:'1', time:'12pm', location:'london'}, {id:6, roomID:'4', time:'4pm', location:'berlin'} ];

let roomMap = rooms.reduce((a,curr)=>{
  a[curr.id] = {roomname : curr.room};
  return a;
},{});
let result = reservations.map((o)=> Object.assign({},o,roomMap[o.roomID]));
console.log(result);

0
你可以利用Map的能力，为一个新对象获取额外的信息。 

var rooms = [{ id: 1, room: 'treehouse' }, { id: 2, room: 'casa' }, { id: 3, room: 'vacation' }, { id: 4, room: 'presidential' }],
    roomMap = new Map(rooms.map(({ id: roomid, room: roomname }) => [roomid, { roomname }])),
    reservations = [{ id: 1, roomID: '2', time: '2pm', location: 'rome' }, { id: 2, roomID: '3', time: '4pm', location: 'paris' }, { id: 3, roomID: '1', time: '4pm', location: 'london' }, { id: 4, roomID: '2', time: '7pm', location: 'rome' }, { id: 5, roomID: '1', time: '12pm', location: 'london' }, { id: 6, roomID: '4', time: '4pm', location: 'berlin' }],
    bookings = reservations.map(o => Object.assign({}, o, roomMap.get(+o.roomID)));

console.log(bookings);
.as-console-wrapper { max-height: 100% !important; top: 0; }

0

var reservations = [
  {id:1, roomID: 2, time:'2pm', location:'rome'},
  {id:2, roomID: 3, time:'4pm', location:'paris'},
  {id:3, roomID: 1, time:'4pm', location:'london'},
  {id:4, roomID: 2, time:'7pm', location:'rome'},
  {id:5, roomID: 1, time:'12pm', location:'london'},
  {id:6, roomID: 4, time:'4pm', location:'berlin'}
];

var rooms = [
     {id:1, room:'treehouse'},
     {id:2, room:'casa'},
     {id:3, room:'vacation'},
     {id:4, room:'presidential'}
];
reservations.forEach(reservation => {
  reservation.roomname = rooms.find(({id}) => id === reservation.roomID).room;
})

console.log(reservations);

0
你可以使用Array.prototype.reduce和Array.prototype.map创建一个查找哈希表，遍历reservations数组并构建所需的输出： 

var rooms = [{id:1, room:'treehouse'},{id:2, room:'casa'},{id:3, room:'vacation'},{id:4, room:'presidential'}];

var reservations = [{id:1, roomID:'2', time:'2pm', location:'rome'},{id:2, roomID:'3', time:'4pm', location:'paris'},{id:3, roomID:'1', time:'4pm', location:'london'},{id:4, roomID:'2', time:'7pm', location:'rome'},{id:5, roomID:'1', time:'12pm', location:'london'},{id:6, roomID:'4', time:'4pm', location:'berlin'}];

var roomHash = rooms.reduce((all, {id, room}) => ({...all, [id]: room }), {});

var result = reservations.map(item => ({...item, room: roomHash[item.roomID]}));

console.log(result);

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