JavaScript Variables

What Are JavaScript Variables?

Variables in JavaScript are used to store data values such as text, numbers, or objects.

Think of a variable like a container that holds information.

Declaring JS Variables

Js uses three keywords to declare variables:

 Example:

Rules for Naming Variables

• Must start with a letter, _ (underscore), or $

• Cannot start with a number

• Cannot use JavaScript reserved words (like class, return)

• JavaScript is case-sensitive (name ≠ Name)

Example:

 Assigning Values

You can declare first, then assign later:

Or declare and assign in one line:

Changing Variable Values

let and var values can be updated:

But const cannot be changed:

 Js Variables Example with Output

Output:

Summary