javascript combine array of object based on a single item object array in ES6

Question

I have the following data

var data = [
  {username:'andy', entries:[{time_in:12, ..},{time_in:334,...}]},
  {username:'andy2', entries:[{time_in:'sr12', ..},{time_in:334,...}]}
]

What am looking forward to get is a final data with

var result = [
  {username:'andy', entry:12},
  {username:'andy', entry:334},
  {username:'andy2', entry:'sr12'},
  {username:'andy2', entry:334},
]

There are more properties per array object but for brevity i have included only username

So i have tried

data.forEach(item=>{
  item.entries.forEach(entry=>{
    //am stuck here
  })
})

You want to merge the objects into a single one? Am I right? — Ajay Gupta
– Ajay Gupta, Commented Jun 25, 2018 at 12:01

VisioN · Accepted Answer · 2018-06-25 12:09:01Z

3

You can use array#reduce with array#forEach. Iterate through each object and for each object iterate through entries array, add the new object in an accumulator.

const data = [
  {username: 'andy', entries: [{time_in: 12}, {time_in: 334}]},
  {username: 'andy2', entries: [{time_in: 'sr12'}, {time_in: 334}]}
]

const result = data.reduce((r, {username, entries}) => {
  entries.forEach(({time_in: entry}) => r.push({username, entry}))
  return r
}, [])

console.log(result)

edited Jun 25, 2018 at 12:09

VisioN

146k35 gold badges287 silver badges291 bronze badges

answered Jun 25, 2018 at 12:04

Hassan Imam

22.6k6 gold badges45 silver badges53 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Leo · Accepted Answer · 2018-06-25 12:06:37Z

0

I think map would do the trick:

var result = data.map((item) => {
    return {
        username: item.username,
        entries: item.entries.length, // Or whatever processing you want
        ...
    }
}

answered Jun 25, 2018 at 12:06

Leo

7516 silver badges15 bronze badges

Comments

ttncrch · Accepted Answer · 2018-06-25 12:15:58Z

0

Here is the immutable version:

const data=[
  {
    username:'andy', entries:[{time_in:12},{time_in:334}]
  }, {
    username:'andy2', entries:[{time_in:'sr12'},{time_in:334}]
  }
];
    

const x = data.reduce((acc, {username, entries}) =>
  acc.concat(
  	entries.map(({time_in}) => ({
        username,
        time_in
    }))
  )
, []);
  
console.log(x);

answered Jun 25, 2018 at 12:15

ttncrch

7,31311 gold badges39 silver badges62 bronze badges

Comments

Ajay Gupta · Accepted Answer · 2018-06-25 12:16:51Z

0

You could do something like this:

const final = [];
data.forEach(item =>
  item.entries.forEach(entry =>
    final.push({ username: item.username, entry: entry.time_in })
  )
);

edited Jun 25, 2018 at 12:16

Ajay Gupta

2,0432 gold badges23 silver badges40 bronze badges

answered Jun 25, 2018 at 12:05

A. Llorente

1,1826 silver badges18 bronze badges

Comments

S. Banegas · Accepted Answer · 2018-06-26 06:32:12Z

0

A possible solution:

const result = data.map(({username, entries}) =>
    entries.map(({time_in})=> ({username: username, entry: time_in}))
).reduce((acc, val) => [...acc, ...val], [])

edited Jun 26, 2018 at 6:32

answered Jun 25, 2018 at 13:21

S. Banegas

12 bronze badges

Collectives™ on Stack Overflow

javascript combine array of object based on a single item object array in ES6

5 Answers 5

Comments

Comments

Comments

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

5 Answers 5

Comments

Comments

Comments

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related