Concepts Problems Playground

Loading...

Built by Antigravity. The source code is available on GitHub.

Learning Path

A step-by-step journey to TypeScript mastery.

Basics

Primitives & Basic Types

Understand the building blocks: string, number, boolean, and the 'any' trap.

Functions & Signatures

Learn how to type function arguments, return values, and callbacks.

Interfaces vs Types

The age-old debate. When to use which and how they differ.

Understand how TS guesses types.

Literal Types & Enums

Lock values to specific strings/numbers and compare with enums.

Fixed-length arrays with positional meaning.

Safety Types: unknown, never, void, object

Safer alternatives to any and how to model impossible or empty values.

Intermediate

Unions & Intersections

Combine types to create powerful and flexible data structures.

Narrowing & Type Guards

Master control flow analysis to write safer code.

Assertions, Non-Null, satisfies

Direct the type checker safely when it cannot infer enough.

typeof, keyof, Indexed Access

Mirror runtime values in the type system for safer reuse.

Access modifiers, interfaces with classes, abstract classes.

Modules & Namespaces

Imports, exports, namespaces, and interop patterns.

Typing Promises and async functions.

tsconfig & Strict Mode

Key compiler flags that keep your codebase safe.

Advanced

Write reusable code that works with any data type.

Partial, Pick, Omit, and other built-in tools to transform types.

Creating new types from existing ones (keyof, in).

Conditional Types

Logic within the type system.

Template Literal Types

String manipulation at the type level.

Ambient & Declaration Merging

Augment third-party types and describe globals safely.