Interactive TypeScript Practice

This free interactive TypeScript practice course is built for developers who already know some JavaScript and want to write safer, more predictable code. Starting from what TypeScript is and how type inference works, you move through every layer of the type system: primitive types, arrays, tuples, union types, literal types, and object shapes. Each concept is reinforced through live code exercises that run directly in your browser, so you get instant feedback instead of reading about theory.

From there the course covers functions with typed parameters, return types, optional parameters, and overloads, then dives into interfaces, type aliases, and class patterns including access modifiers and abstract classes. Generics get their own dedicated module, walking you from basic generic functions through constraints and generic interfaces. You also learn the built-in utility types, from Partial and Pick to Record and beyond, and finish with advanced patterns like type guards, discriminated unions, mapped types, and conditional types.

By the end you will have hands-on experience across all nine modules and can put what you have learned to work immediately, whether that is typing a Node.js API, a React component, or any other project where catching errors at compile time matters. The course is completely free, requires no sign-up to start, and finishing all lessons plus the final exam earns you a certificate of completion you can share on LinkedIn or add to your resume.