TypeScript is a typed superset of JavaScript with the potential to solve many of the headaches for which JavaScript is famous. But TypeScript has a learning curve of its own, and understanding how to use it effectively takes time and practice. Using the format popularized by Effective C++ and Effective Java (both Addison-Wesley), this practical book features 70+ items that give specific advice on what to do and what not to do, and how to think about the language. Author Dan Vanderkam shows you how to apply each item's advice through concrete examples. This book will help you advance from a beginning or intermediate user familiar with TypeScript basics to an expert who knows how to use the language well. Learn the nuts and bolts of TypeScript's type system Design types to make your code safer and more understandable Avoid common gotchas in TypeScript Learn how to write idiomatic TypeScript Make tactical use of the any type Understand how dependencies and type declaration files work in TypeScript Learn how to program at the type level using generic types Successfully migrate your JavaScript codebase to TypeScript Updated for TypeScript 5, this updated second edition includes a new chapter on type-level programming.