How to Declare Multiple Variables in JavaScript

Variables are containers in JavaScript that hold reusable data. They’re like cups filled with stuff that can be used repeatedly depending on how we want to use it.

Here are some JavaScript tips for declaring multiple variables.

Declare Multiple Variables in JavaScript

The most common method for declaring and initializing JavaScript variables is to write each variable on its line.

Example Code:

var cost = 25;
const name = 'Onion';
let currency = 'NPR';

However, there are shorter ways to declare multiple variables in JavaScript. First, you can only use one variable keyword (var, let, or const) and declare variable names and values separated by commas.

Example Code:

let name = 'Shiv', age = 22, message = 'What\'s Up?';

The declaration above is only one line long, but it is more challenging to read than separated declarations. In addition, all variables are declared with the same keyword, let.

Other variable keywords, such as const and var, are not permitted. You can also use comma-separated declarations to create a multi-line declaration.

Example Code:

let name = 'Shiv', age = 22, message = 'What\'s Up?';

Finally, the de-structuring assignment can be used to reveal and preprocess multiple variables in a single line.

Example Code:

const [name, age, message] = ['Shiv', 22, 'What\'s Up?'];
console.log(name);
console.log(age);
console.log(message);

Run Code

The array elements are extracted and assigned to the variables declared on the = operator’s left side in the code above.

Output:

"Shiv"
22
"What's Up?"

The code examples above demonstrate how to declare multiple variables in a single line of JavaScript. Still, declaring variables one by one is the most common method because it separates the declaration into its line, like the following example below.

Example Code:

const name = 'Shiv';
let age = 22;
let message = 'What\'s Up?';
console.log(name);
console.log(age);
console.log(message);

Run Code

As your project grows, the code above will be the easiest to change.

Output:

"Shiv"
22
"What's Up?"

When using comma-separated declaration and de-structuring assignment, you can only use one variable keyword, so you can’t change the variables from const to let without changing them all. In their own way, these variable types are distinct and help speed up code development.

However, it is recommended to use let whenever possible. You can use const whenever the variable’s value must remain constant.