JavaScript - Distinct values in array from array of objects

Question

I have a data like this:

data: [
    {id: 1, name: 'device1', status: ['online','idle']},
    {id: 2, name: 'device2', status: ['network-error']},
    {id: 3, name: 'device3', status: ['online','idle']},
    {id: 4, name: 'device4', status: ['offline','inoperative']},
    
    ...
]

I'm trying to get distinct values of status in an array like this:

['online', 'idle', 'network-error', 'offline', 'inoperative']

I used this code:

let status = [...new Set(data.map(({deviceTags}) => deviceTags))];

But it returns:

[["online", "idle"], ["network-error"], ["online", "idle"], ["offline", "inoperative"]]

How can achieve distinct values of them?

result = [...new Set([your return array here].flat())]

n--
– n--

2021-03-05 13:38:50 +00:00
Commented Mar 5, 2021 at 13:38 — n--
– n--, Commented Mar 5, 2021 at 13:38

3limin4t0r · Accepted Answer · 2021-03-05 14:29:27Z

4

Use .flatMap() instead of .map()

The flatMap() method returns a new array formed by applying a given callback function to each element of the array, and then flattening the result by one level. It is identical to a map() followed by a flat() of depth 1, but slightly more efficient than calling those two methods separately.

const data = [
    {id: 1, name: 'device1', deviceTags: ['online','idle']},
    {id: 2, name: 'device2', deviceTags: ['network-error']},
    {id: 3, name: 'device3', deviceTags: ['online','idle']},
    {id: 4, name: 'device4', deviceTags: ['offline','inoperative']}
]

const status = [...new Set(data.flatMap(({deviceTags}) => deviceTags))];

console.log(status);

edited Mar 5, 2021 at 14:29

3limin4t0r

21.4k3 gold badges38 silver badges61 bronze badges

answered Mar 5, 2021 at 13:42

Andreas

21.9k7 gold badges52 silver badges58 bronze badges

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

Collectives™ on Stack Overflow

JavaScript - Distinct values in array from array of objects

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related