JSFiddle - React, Tailwind, and code Playground

JavaScript

let a = {
	name: 'lala', 
  testArray: [1,2,3], 
  object: {
  	name: 'object', 
    array: [4,5,6]
  }
};

const {name, testArray, object} =  a;

object.array = [...object.array, 0];
console.log(a.object.array);

let b = {
  object2: {
  	name: 'object', 
    array: [4,5,6]
  }
};

const object2 =  {...b.object2};
object2.array = [...object2.array, 0];

console.log(b.object2.array);