destructure variable javascript code example

Example 1: javascript object destructuring

//simple example with object------------------------------
let obj = {name: 'Max', age: 22, address: 'Delhi'};
const {name, age} = obj;

console.log(name);
//expected output: "Max"

console.log(age);
//expected output: 22

console.log(address);
//expected output: Uncaught ReferenceError: address is not defined

// simple example with array-------------------------------
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]

Example 2: js object destructuring with defaults

// Taken from top stack overflow answer

const { dogName = 'snickers' } = { dogName: undefined }
console.log(dogName) // what will it be? 'snickers'!

const { dogName = 'snickers' } = { dogName: null }
console.log(dogName) // what will it be? null!

const { dogName = 'snickers' } = { dogName: false }
console.log(dogName) // what will it be? false!

const { dogName = 'snickers' } = { dogName: 0 }
console.log(dogName) // what will it be? 0!