JavaScript Variables

JavaScript Variables

Variables are used to store data in JavaScript. You can think of them as containers for holding information.

Declaring Variables

In JavaScript, you can declare variables using let, const, or var:

let name = "John"; // A variable that can be reassigned
const age = 25;    // A constant that cannot be reassigned
var city = "Paris"; // An older way to declare variables

Reassigning Variables

Variables declared with let can be reassigned:

let name = "John";
name = "Doe"; // Reassigned
console.log(name); // Output: Doe

However, variables declared with const cannot be reassigned:

const age = 25;
age = 30; // Error: Assignment to constant variable

Rules for Variable Names

1. Variable names must start with a letter, _, or $.
2. They are case-sensitive (Name and name are different).
3. Avoid using reserved keywords (e.g., let, const).

Example

let greeting = "Hello, World!";
console.log(greeting); // Output: Hello, World!

Next: Data Types →