How to get a subset of a javascript object's properties

Question

Say I have an object:

elmo = { 
  color: \'red\',
  annoying: true,
  height: \'unknown\',
  meta: { one: \'1\', two: \'2\'}
};

I want to m

Answer 1

Destructuring assignment with dynamic properties

This solution not only applies to your specific example but is more generally applicable:

const subset2 = (x, y) => ({[x]:a, [y]:b}) => ({[x]:a, [y]:b});

const subset3 = (x, y, z) => ({[x]:a, [y]:b, [z]:c}) => ({[x]:a, [y]:b, [z]:c});

// const subset4...etc.


const o = {a:1, b:2, c:3, d:4, e:5};


const pickBD = subset2("b", "d");
const pickACE = subset3("a", "c", "e");


console.log(
  pickBD(o), // {b:2, d:4}
  pickACE(o) // {a:1, c:3, e:5}
);

You can easily define subset4 etc. to take more properties into account.