add properties to output object and convert to array of object-CodePudding

This is my request body which I am sending to back end,

{
    "appId":'10001',
    "upstream":[
        {
          "name":"john",
          "content":"APPLICATION 1"
        },
        {
          "name":"peter",
          "content":"APPLICATION 2"
        },
    ],
    "downstream":[
        {
          "name":"max",
          "content":"APPLICATION 3"
        },
{
          "name":"justin",
          "content":"APPLICATION 4"
        },

    ],
}

I want to convert the same like below,

[
 {
    "appId":'10001',
    "name":"john",
    "content":"APPLICATION 1",
    "type":"upstream"
 },
 {
    "appId":'10001',
    "name":"peter",
    "content":"APPLICATION 2",
    "type":"upstream"
 },
 {
    "appId":'10001',
    "name":"max",
    "content":"APPLICATION 3",
    "type":"downstream"
 },
 {
    "appId":'10001',
    "name":"justin",
    "content":"APPLICATION 4",
    "type":"downstream"
 },
]

This needs to be done using Javascript (ES6).with the help of map function or any other ES6 utilities.

Thanks in advance.

CodePudding user response：

An improved solution using modern syntax can be:

const input = {
  appId: "10001",
  upstream: [
    {
      name: "john",
      content: "APPLICATION 1",
    },
    {
      name: "peter",
      content: "APPLICATION 2",
    },
  ],
  downstream: [
    {
      name: "max",
      content: "APPLICATION 3",
    },
    {
      name: "justin",
      content: "APPLICATION 4",
    },
  ],
};

const upstreams = input.upstream.map((v) => ({ appId: input.appId, ...v, type: "upstream" }));
const downstreams = input.downstream.map((v) => ({ appId: input.appId, ...v, type: "downstream" }));
const results = [...upstreams, ...downstreams];

console.log(results);

Here, we're creating a new array upstreams, which will be filled with the results of calling the first array of objects in input and adding to it additional key-value pairs (appId and the appropriate type). Same for the downstreams array.

We used the spread operator ... to quickly copy all of an existing array/object into another array/object.

And the keyword const instead of var since we're not going to mutate all used symbols.

CodePudding user response：

If you only want to convert it -

var input = {
    "appId": '10001',
    "upstream": [
        {
            "name": "john",
            "content": "APPLICATION 1"
        },
        {
            "name": "peter",
            "content": "APPLICATION 2"
        },
    ],
    "downstream": [
        {
            "name": "max",
            "content": "APPLICATION 3"
        },
        {
            "name": "justin",
            "content": "APPLICATION 4"
        },
    ],
};

var upstreams = input.upstream.map(v => { return {appId: input.appId, name: v.name, content: v.content, type: 'upstream'} });
var downstreams = input.downstream.map(v => { return {appId: input.appId, name: v.name, content: v.content, type: 'downstream'} });
var result = upstreams.concat(downstreams);
console.log(result);