JAVASCRIPT

javascript destructuring

const [a, b] = array;
const [a, , b] = array;
const [a = aDefault, b] = array;
const [a, b, ...rest] = array;
const [a, , b, ...rest] = array;
const [a, b, ...{ pop, push }] = array;
const [a, b, ...[c, d]] = array;

const { a, b } = obj;
const { a: a1, b: b1 } = obj;
const { a: a1 = aDefault, b = bDefault } = obj;
const { a, b, ...rest } = obj;
const { a: a1, b: b1, ...rest } = obj;

let a, b, a1, b1, c, d, rest, pop, push;
[a, b] = array;
[a, , b] = array;
[a = aDefault, b] = array;
[a, b, ...rest] = array;
[a, , b, ...rest] = array;
[a, b, ...{ pop, push }] = array;
[a, b, ...[c, d]] = array;

({ a, b } = obj); // brackets are required
({ a: a1, b: b1 } = obj);
({ a: a1 = aDefault, b = bDefault } = obj);
({ a, b, ...rest } = obj);
({ a: a1, b: b1, ...rest } = obj);

destructuring object

const obj = {
  name: "Fred",
  age: 42,
  id: 1
}

//simple destructuring
const { name } = obj;
console.log("name", name);

//assigning multiple variables at one time
const { age, id } = obj;
console.log("age", age);
console.log("id", id);

//using different names for the properties
const { name: personName } = obj;
console.log("personName", personName);
 Run code snippet

destructuring

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

// without destructuring
var one   = foo[0];
var two   = foo[1];
var three = foo[2];

// with destructuring
var [one, two, three] = foo;

js destructuring

let [person, age] = ['John', 26]
let msg = `${person} is ${age} years old`
console.log(msg)

destructuring in javascript

/*
Array Destructuring: The following example shows us how to convert all 
the elements of an array to a variable.

Object Destructuring: The following example shows us how to convert all 
the properties of an object into a variable.
*/
//Array Destructuring
const friends = ['Bill', 'Gates'];
const [firstName, secondName] = friends;
console.log(secondName);  //Gates

//Object Destructuring
const person = {name: "Bill Gates", age: 17, phone: "123456789"};
const {name} = person;
console.log(name);  //Bill Gates

JavaScript Destructuring

// before you would do something like this
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

destructuring js

console.log('Hello World') // Hello World

const {log} = console;
log('Hello World') // Hello World

js-destructuring

const getTemperature = ({ celsius = 15 } = {}) => celsius;

destructuring javascript

let a, b, rest;
[a, b] = [10, 20];
console.log(a); // 10
console.log(b); // 20

[a, b, ...rest] = [10, 20, 30, 40, 50];
console.log(a); // 10
console.log(b); // 20
console.log(rest); // [30, 40, 50]

({ a, b } = { a: 10, b: 20 });
console.log(a); // 10
console.log(b); // 20

// Stage 4(finished) proposal
({a, b, ...rest} = {a: 10, b: 20, c: 30, d: 40});
console.log(a); // 10
console.log(b); // 20
console.log(rest); // {c: 30, d: 40}

js destructuring explained

const { identifier } = expression;

js-destructuring

const getTemperature = (atticData) => atticData?.celsius ?? 15;
// insted do
const getTemperature = ({ celsius = 15 } = {}) => celsius;

// https://realworldjs.medium.com/never-use-the-dot-operator-in-javascript-ee0339d85fb

js destructuring

/*simple example*/
const [name, age] = ["malek","25"];

destructuring

const doggie = {
  name: 'Buzz',
  breed: 'Great Pyrenees',
  furColor: 'black and white',
  activityLevel: 'sloth-like',
  favoriteFoods: {
    meats:{
      ham: 'smoked',
      hotDog: 'Oscar Meyer',
    },
    cheeses:{
      american: 'kraft'
    }
  }
};

const { ham, hotDog } = doggie.favoriteFoods.meats;
ham; // => "smoked"
hotDog; // => "Oscar Meyer"

Destructuring in javascript

const { name, age, job } = { name: 'abrar', age: 24, job: 'web-developer' }
console.log(name, age, job)

js destructuring

function calculatefood (food, tip) {
    tip_percent = tip / 100;
    tip_amount = food * tip_percent;
    total = food + tip_amount;
    return [tip_amount, total];
}
const [tip, sum] = calculatefood(100, 20);
console.log(tip);
console.log(sum);