javascript destructuring an object code example

Example 1: object destructuring

const book = {
    title: 'Ego is the Enemy',
    author: 'Ryan Holiday',
    publisher: {
        name: 'Penguin',
        type: 'private'
    }
};

const {title: bookName =  'Ego', author, name: {publisher: { name }} = book, type: {publisher: { type }} = book } = book;

Example 2: javascript deconstruct object

const objA = {
 prop1: 'foo',
 prop2: {
   prop2a: 'bar',
   prop2b: 'baz',
 },
};

// Deconstruct nested props
const { prop1, prop2: { prop2a, prop2b } } = objA;

console.log(prop1);  // 'foo'
console.log(prop2a); // 'bar'
console.log(prop2b); // 'baz'

Example 3: javascript function destructuring

function f() {
  return [1, 2];
}

let a, b; 
[a, b] = f(); 
console.log(a); // 1
console.log(b); // 2

Example 4: object destructuring

let a, b, rest;
[a, b] = [10, 20];

console.log(a);
// expected output: 10

console.log(b);
// expected output: 20

[a, b, ...rest] = [10, 20, 30, 40, 50];

console.log(rest);
// expected output: Array [30,40,50]