Is there a way to destructure an object into a new object in es6?

Question

For instance, I have this object:

const payload = {
    apple: 1,
    dog: 2,
    cat: 3
}

and I want to destructure it into a new object that only contains apple and dog:

const newPayload = {
    apple:1,
    dog: 2
}

Something like:

const {{apple, dog} : newPayload} = payload

Obviously the above is wrong, but wondering if there is a way to do something like this.

Thanks!

this isn't "destructuring" (that would be converting from a tuple to individual named variables), but a shallow-copy with a property filter. — Dai, May 17 '18 at 00:14
this way is ugly ... `const newPayload = (({apple, dog}) => ({apple, dog}))(payload)` — Jaromanda X, May 17 '18 at 00:18
Possible duplicate of [Filter object properties by key in ES6](https://stackoverflow.com/questions/38750705/filter-object-properties-by-key-in-es6) — Dai, May 17 '18 at 00:18
@Dai No, this is not duplicate of that question. This is different — Zohaib Ijaz, May 17 '18 at 00:23
the benefit of my ugly code is ... no spurious const's littering the code :p — Jaromanda X, May 17 '18 at 00:24
@ZohaibIjaz how is it not a duplicate? This Q's OP wants to clone an object using only a subset of that object's properties, that's exactly what's going on in the linked QA. — Dai, May 17 '18 at 00:24
OP is looking for destructing based solution, which is not there in your specified link. — Zohaib Ijaz, May 17 '18 at 00:26
a less ugly non polluting way is `const newPayload = (({ cat, ...x }) => x)(payload);` — Jaromanda X, May 17 '18 at 00:36
@JaromandaX What is this technique or concept called `const newPayload = (({apple, dog}) => ({apple, dog}))(payload)`? I want to read about it and how it works. Thanks — newbie, Nov 26 '22 at 00:16

score 11 · Accepted Answer · answered May 17 '18 at 00:18

11

You could use delete:

const newPayload = { ...payload };

delete newPayload.cat

Or:

const { cat, ...newPayload } = payload;

Lodash also has omit():

const newPayload = _.omit(payload, ['cat']);

answered May 17 '18 at 00:18

Anthony

`const { cat, ...newPayload } = payload;` is exactly what I had in mind. Thanks! – reectrix May 17 '18 at 00:26
1

if you want to avoid littering the context with `consts` ... `const newPayload = (({ cat, ...x }) => x)(payload);` – Jaromanda X May 17 '18 at 00:35

score 5 · Answer 2 · answered May 17 '18 at 00:23

5

Probably in two steps:

const payload = {
    apple: 1,
    dog: 2,
    cat: 3
}

const { apple, dog } = payload

const newPayload = {
    apple,
    dog,
}

Or you can use lodash _.pick :

const newPayload = _.pick(payload, ['apple', 'dog'])

answered May 17 '18 at 00:23

Matt Aft

2 Answers2