JS Tutorial

JavaScript Variables

In JavaScript, variables are used to store data values. Think of variables as containers that hold reusable pieces of information like numbers, text, or more complex data types.

🛠️ Declaring Variables

You can declare variables using var, let, or const:

// Using var
var name = "John";

// Using let
let age = 25;

// Using const (value can't change)
const country = "India";
  

• var — Old way, avoid it in modern code.
• let — Use when the value can change later.
• const — Use when the value should stay constant.

📦 Variable Types

Variables can store different types of data:

• String: Text inside quotes → "Hello"
• Number: Integers or decimals → 42, 3.14
• Boolean: true or false
• Array: List of values → [1, 2, 3]
• Object: Key-value pairs → {name: "John"}

🧪 Live Example:

Click the button to see JavaScript variables in action:

🧠 Important Notes

• Declare before using: Always declare variables before using them to avoid errors.
• const is best: Prefer const unless you know the value will change.
• Names must start with a letter, _ or $ (not numbers).