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;// 1) Destructure array items
const [first, second,, fourth] = [10, 20, 30, 40];
// 2) Destructure object properties
const { PI, E, SQRT2 } = Math;const hero = {
name: 'Batman',
realName: 'Bruce Wayne',
address: {
city: 'Gotham'
}
};
// Object destructuring:
const { realName, address: { city } } = hero;
city; // => 'Gotham'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// 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// 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