How to assign multiple variables at once in JavaScript?
In ES6 you can do it this way:
var [a, b] = ["one", "two"];
The above code is ES6 notation and is called array destructuring/object destructuring (if it's an object).
You provide the array on the right-hand side of the expression and you have comma-separated variables surrounded by square brackets on the left-hand side.
The first variable maps to the first array value and so on.
While you cannot do var a, b = "one", "two";
, and get them assigned to each variable in the respective order, you can do:
var a, b;
to initialize these variables as undefined
.
You can also do var a, b = 'foo';
to assign b to 'foo', while initializing 'a' as undefined
.
var a, b;
> a
--> undefined
> b
--> undefined
> var d, e;
> e
--> undefined
> f
--> Uncaught ReferenceError: f is not defined
> var c, g = 'foo';
> c
--> undefined
> g
--> "foo"
Object destructuring
looks like:
const user = {
id: 42,
is_verified: true
};
const {id, is_verified} = user;
console.log(id); // 42
console.log(is_verified); // true
You will also see this in JavaScript to import members of a module:
Import multiple exports from module. This inserts both foo and bar into the current scope.
import {foo, bar} from '/modules/my-module.js';