Skip to the chapter
←TypeScriptGGroundworkTSTypeScript
TypeScript/Intermediate/I2
10 / 29 written chapters
The cover
  1. B1Setup & compiler
  2. B2Basic types
  3. B3Functions
  4. B4Interfaces & aliases
  5. B5Union & intersection
  6. B6Enums & literals
  7. B7Classes
  8. B8DOM & JSON
  1. I1Structural typing
  2. I2Narrowing
  3. I3Runtime validation
  4. I4Generics
  5. I5Utility types
  6. I6Mapped & conditional
  7. I7Modules & .d.ts
  8. I8tsconfig in depth
  9. I9Third-party types
  10. I10Typing async code
  11. I11Testing typed code
  1. A1Advanced generics
  2. A2Conditional & recursive types
  3. A3Type-level programming
  4. A4Decorators & metadata
  5. A5Structural vs nominal
  6. A6Type-check performance
  7. A7Monorepo setups
  8. A8Migrating from JS
  9. A9Compiler API
  10. A10End-to-end type safety

TSI2 · Part 2 · Intermediate

Narrowing

Not written yet.
10 of 29

Sketch only

01This chapter will cover

Narrowing

  • typeof/in/instanceof guards, custom type guards
  • Discriminated unions

→Next stop

  1. I1Previous · I1Structural typing & inference in depth
  3. I2you are here
  5. Next · I3Runtime validation with ZodNext chapter

01Meanwhile

  • JavaScript is written, start there
  • R3 · JavaScript & TS covers this in the interview book