const nums = [1, 2, 3];
const obj = { a: 1, b: 2 };
const newObj = { ...obj, b: 3, ...obj };

const arr1 = [4, 5];
const arr2 = [6, 7];
const combined = [...nums, ...arr1, ...arr2];

const [first, ...rest] = combined;
const { a, ...remaining } = newObj;

console.log(newObj.b);
console.log(rest.length);
console.log(remaining.b);