ES6 - Destructuring assignment - Unpack some properties from existing object to a new object? [duplicate]

Answer 1

If you know the specific keys you're going to need in the new Object, I would use good old Object.assign

const extendInfo = { //object containing properties to extend other object  }
const abc = { //your obj to extend }
Object.assign(abc, { a: extendInfo.a, b: extendInfo.b, c: extendInfo.c });

If you have a lot of props to extract the syntax becomes heavier and I would suggest a different approach, but if it's just a couple props, I think this is the cleaner and faster approach - and technically one line if you don't count variable declarations

Answer 2

Using destructuring the params and IIFE (Immediately invoked function expressions), we can get rid of the unwanted keys in the source objects.

const test = {a:1, b:2, c:3, d:4, e:5 };
const abc = (({a,b,c}) => ({a, b, c}))(test);
console.log(abc);

For ES5 compatibility,

var test = {a:1, b:2, c:3, d:4, e:5 };
    
var abc = (function (test) {
  return {
    a: test.a,
    b: test.b,
    c: test.c
  }
})(test);

console.log(abc);

Answer 3

You can use object rest to destructure your initial object:

const test = {a:1, b:2, c:3, d:4, e:5 };
const {d, e, ...abc} = { ...test, f: 6};

console.log(abc);