JAVASCRIPT

object destructuring javascript

// destructuring object & nested object & combine object into single object
let user = {
  name: 'Mike',
  friend: ["John", "Paul", "Jimmy"],
  location: {
    region:"England",
    country:"United Kingdom"
  },
  aboutMe: {
    status: "Single",
    pet: "Dog",
  }
}

const { name, friend, location, aboutMe: {status , pet} } = user;

console.log(name); // output: "Mike"
console.log(friend);  // output: [ 'John', 'Paul', 'Jimmy' ]
console.log(location); // output: { region: 'England', country: 'United Kingdom' }
console.log(status); // output: "Single"
console.log(pet); // output: "Dog"

//Combining Obj
const newUser = {
  ...user,
  car: {
    make: "Buick",
    year: 2012,
  }
}

console.log(newUser)
// output user obj + car object into one
// {
//   name: 'Mike',
//   friend: [ 'John', 'Paul', 'Jimmy' ],
//   location: { region: 'England', country: 'United Kingdom' },
//   aboutMe: { status: 'Single', pet: 'Dog' },
//   car: { make: 'Buick', year: 2012 }
// }

//Bonus destructuring from object of array
const {friend: [a, ...b]} = user
console.log(a) // output: "John"
console.log(b) // output: ["Paul", "Jimmy"]

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]

js object destructuring

const hero = {  
  name: 'Batman',  
  realName: 'Bruce Wayne'
};

const { name, realName } = hero;

name;     // => 'Batman',
realName; // => 'Bruce Wayne'

object destructuring into this

const demo = { nextUrl: 'nextUrl', posts: 'posts' };

const target = {}; // replace target with this

({ nextUrl: target.nextUrl, posts: target.communityPosts } = demo);

console.log(target);

array destructuring

//Without destructuring

const myArray = ["a", "b", "c"];

const x = myArray[0];
const y = myArray[1];

console.log(x, y); // "a" "b"

//With destructuring

const myArray = ["a", "b", "c"];

const [x, y] = myArray; // That's it !

console.log(x, y); // "a" "b"

How to Destructuring Array in Javascript?

//destructuring array 
const alphabet = ['a', 'b', 'c', 'b', 'e'];
const [a, b] = alphabet;
console.log(a, b);
//Expected output: a b

Array destructuring JS

// In an array destructuring from an array of length N specified on the right-hand side of the assignment, if the number of variables specified on the left-hand side of the assignment is greater than N, only the first N variables are assigned values. The values of the remaining variables will be undefined.

const foo = ['one', 'two'];

const [red, yellow, green, blue] = foo;
console.log(red); // "one"
console.log(yellow); // "two"
console.log(green); // undefined
console.log(blue);  //undefined

destructuring an object js

const user = { id: 42, isVerified: true }

// grabs the property by name in the object, ignores the order
const { isVerified, id } = user;

console.log(isVerified);
// > true

Destructuring in ES6

var a = obj.a
var b = obj.b
var c = obj.c

Destructuring of object in ES6

function printBasicInfo({firstName, secondName, profession}) {
	console.log(firstName + ' ' + secondName + ' - ' + profession)
}

var person = {
  firstName: 'John',
  secondName: 'Smith',
  age: 33,
  children: 3,
  profession: 'teacher'
}

printBasicInfo(person)

object destructuring ES6

const person = {
    name: 'John',
    age: 34,
    hobbies: {
        read: true,
        playGames: true
    }
}
 
let {name, hobbies: {read, playGames}} = person;

console.log(person);
console.log(name);
console.log(read,playGames);

Array Destructuring

const foo = ['one', 'two', 'three'];

const [red, yellow, green] = foo;
console.log(red); // "one"
console.log(yellow); // "two"
console.log(green); // "three"

How to destructure arrays and objects in javascript?

// Array to destructure
const arr = ["Wissam", "Fawzi", "Darwich", "Fawaz"];
// First element, second element, and then remaining ones
const [firstName, middleName, ...restOfName] = arr;
console.log(firstName); // Wissam
console.log(middleName); // Fawzi
console.log(restOfName.join(" ")); // Darwich Fawaz

// Object to destructure
const socialMedia = {
  twitter: "@wissam_f",
  facebook: "https://www.facebook.com/wissam.fawaz",
  linkedin: "https://www.linkedin.com/in/wissam-fawaz-6b440839/",
};
// To extract values, property keys should be used
const {twitter, linkedin} = socialMedia;
// Twitter: @wissam_f
console.log("Twitter:", twitter);
// LinkedIn: https://www.linkedin.com/in/wissam-fawaz-6b440839/
console.log("LinkedIn:", linkedin);

Javascript array destructuring

let [a, b] = [9, 5]
[b, a] = [a, b]
console.log(a, b);
//Expected output: 5,9

javascript Array Destructuring

const arrValue = ['one', 'two', 'three'];

// destructuring assignment in arrays
const [x, y, z] = arrValue;

console.log(x); // one
console.log(y); // two
console.log(z); // three

JavaScript Destructuring - From ES6

// assigning object attributes to variables
const person = {
    name: 'Sara',
    age: 25,
    gender: 'female'    
}

// destructuring assignment
let { name, age, gender } = person;

console.log(name); // Sara
console.log(age); // 25
console.log(gender); // female

object destructuring example

const hero = {
  name: 'Batman',
  realName: 'Bruce Wayne',
  address: {
    city: 'Gotham'
  }
};

// Object destructuring:
const { realName, address: { city } } = hero;
city; // => 'Gotham'

object destructuring ES6

let person = {
    name: 'John',
    age: 21,
    gender: 'male'
}

let { name, age, gender } = person;

console.log(name, age, gender);

js Destructuring arrays and objects

// 1) Destructure array items
const [first, second,, fourth] = [10, 20, 30, 40];

// 2) Destructure object properties
const { PI, E, SQRT2 } = Math;

Destructuring of array in ES6

function printFirstAndSecondElement([first, second]) {
    console.log('First element is ' + first + ', second is ' + second)
}

function printSecondAndFourthElement([, second, , fourth]) {
    console.log('Second element is ' + second + ', fourth is ' + fourth)
}

var array = [1, 2, 3, 4, 5]

printFirstAndSecondElement(array)
printSecondAndFourthElement(array)

js object destructuring

const { [propName]: identifier } = expression;

destructuring an array

let cars = ['ferrari', 'tesla', 'cadillac'];
let [car1, car2, car3] = cars;
console.log(car1, car2, car3); // Prints: ferrari tesla cadillac

Destructuring in ES6

let {a, b, c} = obj

array destructuring in js

const arr = [1, 2, 3, 4];
const [first, second] = arr; // first = 1, second = 2

js The equivalent of destructuring arrays and objects

// 1) assuming arr is [10, 20, 30, 40]
const first = arr[0];
const second = arr[1];
// third element skipped
const fourth = arr[3];

// 2)
const PI = Math.PI;
const E = Math.E;
const SQRT2 = Math.SQRT2;

JavaScript Destructuring - Before ES6

// assigning object attributes to variables
const person = {
    name: 'Sara',
    age: 25,
    gender: 'female'    
}

let name = person.name;
let age = person.age;
let gender = person.gender;

console.log(name); // Sara
console.log(age); // 25
console.log(gender); // female

object destructuring in javascript

const hero = {
  name: 'Batman'
};
// Object destructuring:
const { name: heroName } = hero;
heroName; // => 'Batman'

javascript object destructuring

// In this syntax:

let { property1: variable1, property2: variable2 } = object;

// The identifier before the colon (:) is the property of the object and the identifier after the colon is the variable.

destructuring array ES6

let a = 8, b = 6;
[a, b] = [b, a];

object destructuring ES6

let person = {
    name: 'John',
    age: 21,
    gender: 'male'
}

let { name : name1, age: age1, gender:gender1 } = person;

console.log(name1, age1, gender1);

Array destructuring

let [name, team] = ["Bob", "100Devs"]

console.log(name)//"Bob"
console.log(team)//"100Devs"

destructuring an object in JS

let person = {
    firstName: 'John',
    lastName: 'Doe'
};
Code language: JavaScript (javascript)