javascript destructuring examples

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: destructuring assignment

Destructuring assignment is special syntax introduced in ES6, 
for neatly assigning values taken directly from an object.

const user = { name: 'John Doe', age: 34 };

const { name, age } = user;
// name = 'John Doe', age = 34

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: how destructuring works in javascript

//destructuring in javascript
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 5: mdn destructuring

const x = [1, 2, 3, 4, 5];
const [y, z] = x;
console.log(y); // 1
console.log(z); // 2

Example 6: js object destructuring

const { [propName]: identifier } = expression;