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16+ lessons available

Across 2 learning tracks

🔒 ts-playground.vercel.app

Variables

beginner

TypeScript inherits JS's three ways to declare variables…

Your task

Declare a const named greeting

index.ts__tests__.ts

1export const greeting = "Hello, World!";

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▶ Run Tests

✅ All tests passed

Learning Tracks

JS8 lessons

JavaScript

Core JS fundamentals — variables, functions, closures, async, and more.

Re8 lessons

React

Build UIs with React — JSX, components, hooks, and state management.

Live Editor

Write TypeScript and React with syntax highlighting, instant preview, and console output.

Guided Lessons

Clear instructions, starter code, and solution hints — learn one concept at a time.

Auto-graded

Run tests in the browser and get immediate pass/fail feedback on your code.

What you'll learn

Variables, types, and type inference

Functions with typed parameters

Interfaces and custom types

JSX and component composition

Props, state, and event handlers

React hooks (useState, useEffect)

Someone from Egypt started the JavaScript track recently

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