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TypeScript

Type-safe JavaScript. Types, generics, and real-world patterns.

Browse 41 tutorials → Other topics

Why learn TypeScript?

  • Catches a class of bugs at compile time that JavaScript only finds in production.

  • Industry-standard for any non-trivial JS codebase in 2026.

  • Editor autocomplete and refactoring become dramatically better.

  • Adopts incrementally — drop it into existing JS one file at a time.

What you can build with TypeScript

Large-scale React/Next.js apps Node.js backends Shared types between frontend and backend Library authoring

TypeScript tutorials

41 articles · page 1 of 3

Hand-written tutorials, ordered as a recommended learning path.

  1. 01 What is TypeScript? A clear, professional introduction to TypeScript — what it is, how it relates to JavaScript, why teams adopt it, and what you can build with it as a beginner.
  2. 02 Basic Types A complete beginner's tour of TypeScript's primitive types, arrays, tuples, literal types, any, unknown, and the null and undefined story — with runnable examples.
  3. 03 Interfaces & Type Aliases A complete beginner's guide to interfaces and type aliases in TypeScript — how to declare object shapes, when to choose each, and how to extend and combine them.
  4. 04 Typing Functions A practical, beginner-friendly guide to typing functions in TypeScript — parameter and return types, optional and default parameters, rest parameters, callbacks, and overloads.
  5. 05 Generics Basics A clear, runnable introduction to TypeScript generics — what they are, why they exist, how to write generic functions and types, and how constraints keep them honest.
  6. 06 Enums & Literals A practical guide to enums and literal types in TypeScript — string enums, number enums, const enums, literal unions as a lighter alternative, and discriminated unions.
  7. 07 Narrowing & Guards A practical guide to narrowing in TypeScript — typeof, instanceof, in, discriminated unions, custom predicates with `x is T`, assertion functions, and exhaustive checks with never.
  8. 08 Modules & Imports A practical guide to TypeScript modules — ESM imports and exports, type-only imports, default vs named exports, barrel files, and how tsconfig moduleResolution decides what gets resolved.
  9. 09 tsconfig Deep Dive A comprehensive guide to tsconfig.json covering compiler options, module resolution, path aliases, project references, and recommended configurations.
  10. 10 Advanced Generics Master advanced TypeScript generics patterns including conditional constraints, recursive types, generic factories, and type-safe builder patterns with examples.
  11. 11 Type Guards & Narrowing Learn how TypeScript type guards and control flow narrowing work, including typeof, instanceof, in, discriminated unions, and custom type predicates.
  12. 12 Utility Types Guide A comprehensive guide to all built-in TypeScript utility types including Partial, Required, Pick, Omit, Record, Extract, Exclude, and more with practical examples.
  13. 13 Pulumi IaC Learn how Pulumi lets you define cloud infrastructure using TypeScript, Python, or Go instead of domain-specific languages.
  14. 14 Assertion Functions Use assertion functions to narrow types at runtime, replacing manual throw-and-cast patterns with compiler-understood safety checks.
  15. 15 Builder Pattern Implement the builder pattern in TypeScript with compile-time enforcement of required fields using generics and conditional types.
  16. 16 Declaration Files Learn how TypeScript declaration files work, when to write your own .d.ts files, and how to type untyped JavaScript libraries.
  17. 17 Project References Set up TypeScript project references to manage multi-package monorepos with incremental builds, clean boundaries, and fast compilation.
  18. 18 typeof & keyof Master the typeof and keyof type operators to derive types from values and extract object keys for type-safe lookups and mappings.
  19. 19 Advanced Conditionals Go beyond basic conditional types with infer, recursive conditionals, and distributive patterns to build powerful type-level programs.
  20. 20 const Assertions Deep dive into as const for literal types, readonly arrays, and deeply immutable objects in TypeScript.