destructuring array and object

console.log("Hello World!");
let a = 1;
let b= 2;
[a, b] = [b, a]
console.log(a,b);
let firstName="John";
let lastName="Doe";
({firstName, lastName, age} = {
    firstName: "Doe",
    lastName: "John",
    age: 18
});
console.log(firstName, lastName, age);