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Lesson 2 of 10

Variables & Data Types

Variables store data. Use let for values that change, const for values that do not, and avoid var in modern code.

Common data types: string (text), number, boolean (true/false), null, undefined, and object.

JS
let name = "Ali";
const age = 25;
let isStudent = true;
let score = 95.5;

console.log(name); // "Ali"
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You completed JavaScript!

You finished all 10 lessons and quizzes. You now know the basics of JavaScript.