JavaScript Sensei Lite
Master the fundamentals of JavaScript
Fundamentals
Variables & Data Types
Variables are containers for storing data values. In JavaScript, you can declare variables using three keywords:
• var - Function-scoped, can be redeclared
• let - Block-scoped, can be reassigned
• const - Block-scoped, cannot be reassigned
JavaScript has several data types:
• String - Text data
• Number - Numeric data
• Boolean - true or false
• Object - Collections of key-value pairs
• Array - Ordered lists of values
• undefined - Variable declared but not assigned
• null - Intentional absence of value
Examples:
let name = "John";const age = 25;var isActive = true;Code Sandbox
// Write your JavaScript code here
console.log("Hello, World!");
Output will appear here...