CODEWITHSUNDEEP
javascriptarraysobject
Mario Hess
Mario Hess

Reputation: 167

How to transform an object to an array with nested objects?

I got an object which contains some values.

How do i transform this properly?

I tried multiple things like includes(), find(), some(), for-loops, but it seems like the check if 'conversationWith' is included in the object is failing.

The object looks like this:


    {
  _id: 5d3eed4b8558ab0fc513a3b5,
  subject: 'Subject',
  message: 'Message',
  newMessage: true,
  from: 5d3b0585181c521610a15241,
  fromName: 'John Doe',
  to: 5d3b0749c9b633171fa62a48,
  toName: 'Leeroy Jenkins',
  conversationWith: 'Leeroy Jenkins'
}
{
  _id: 5d3eed608558ab0fc513a3b7,
  subject: '2nd',
  message: '2nd',
  newMessage: true,
  from: 5d3b0585181c521610a15241,
  fromName: 'John Doe',
  to: 5d3b0749c9b633171fa62a48,
  toName: 'Leeroy Jenkins',
  conversationWith: 'Leeroy Jenkins'
}
{
  _id: 5d3ef15e6a570c1201457918,
  subject: '3rd',
  message: '3rd',
  newMessage: true,
  from: 5d3b0585181c521610a15241,
  fromName: 'John Doe',
  to: 5d3b0749c9b633171fa62a48,
  toName: 'Leeroy Jenkins',
  conversationWith: 'Leeroy Jenkins'
}

I want to create an array like this out of it:


    [{ 
       conversationWith: "Leeroy Jenkins",
       message: ["Message", "2nd", "3rd"]
    }]

The Problem is that i have multiple objects that I'm looping through, where I only want the 'conversationWith' property to be inserted into the array once, while i want all the messages in it.

I either get the 'conversationWith' property inserted multiple times or not at all.

Upvotes: 1

Views: 100

Answers (2)

ellipsis
ellipsis

Reputation: 12152

You can use a simple forEach loop

var a= [{
  _id: '5d3eed4b8558ab0fc513a3b5',
  subject: 'Subject',
  message: 'Message',
  newMessage: true,
  from: '5d3b0585181c521610a15241',
  fromName: 'John Doe',
  to: '5d3b0749c9b633171fa62a48',
  toName: 'Leeroy Jenkins',
  conversationWith: 'Leeroy Jenkins'
},
{
  _id: '5d3eed608558ab0fc513a3b7',
  subject: '2nd',
  message: '2nd',
  newMessage: true,
  from: '5d3b0585181c521610a15241',
  fromName: 'John Doe',
  to: '5d3b0749c9b633171fa62a48',
  toName: 'Leeroy Jenkins',
  conversationWith: 'Leeroy Jenkins'
},
{
  _id: '5d3ef15e6a570c1201457918',
  subject: '3rd',
  message: '3rd',
  newMessage: true,
  from: '5d3b0585181c521610a15241',
  fromName: 'John Doe',
  to: '5d3b0749c9b633171fa62a48',
  toName: 'Leeroy Jenkins',
  conversationWith: 'Leeroy Jenkins'
}]
    var b=[];
    var bool=false;
    a.forEach(function(e){
        b.forEach(function(k){
            if(k.conversationWith==e.conversationWith)
            {
                bool=true;
                k.message.push(e.message)
            }
        })
        if(bool==false)
        {
            var obj={};
            obj.conversationWith=e.conversationWith;
            obj.message=[];
            obj.message.push(e.message);
            b.push(obj);
        }
        bool=false;
    })
    console.log(b)

Upvotes: 2

parallaxis
parallaxis

Reputation: 196

Array reduce approach

The reduce() method executes a reducer function (that you provide) on each element of the array, resulting in a single output value.

use Array.prototype.reduce to return an array of new objects created from source array with Array.prototype.some and Array.prototype.filter and Array.prototype.map and Array.prototype.join to fitler and join the messages together

https://repl.it/repls/TealVitalDatum

const LEROY = 'Leeroy Jenkins';
const convoWithMessage = [{
      _id: '5d3eed4b8558ab0fc513a3b4',
      subject: 'Subject',
      message: 'Message',
      newMessage: true,
      from: '5d3b0585181c521610a15241',
      fromName: 'John Doe',
      to: '5d3b0749c9b633171fa62a48',
      toName: 'Leeroy Jenkins',
      conversationWith: 'John Doe'
    }, {
      _id: '5d3eed4b8558ab0fc513a3b4',
      subject: 'Subject',
      message: 'Message',
      newMessage: true,
      from: '5d3b0585181c521610a15241',
      fromName: 'John Doe',
      to: '5d3b0749c9b633171fa62a48',
      toName: 'Leeroy Jenkins',
      conversationWith: 'John Doe'
    }].reduce((acc, item, index, array) => {
        const isLeroy = d => d.toName === LEROY;
        const leroys = acc.filter(isLeroy);
        if (item.toName === LEROY) {
            if (array.some(isLeroy)) {
                const message = [item.message, ...leroys.map(i => i.message)];
          return [...leroys.filter(isLeroy), { name: LEROY, message }]
            }
        }
    return [...acc, { toName: item.toName, message: item.message }];
    }, [])

    console.log(convoWithMessage)

Upvotes: 0

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