Handwritten notes · Part 14
TypeScript Handwritten Notes for Placements (Free PDF)
By Gaurav SharmaPublished
26 pages of handwritten-style TypeScript notes for placements and interviews: basic types, any vs unknown vs never, type vs interface, narrowing, discriminated unions, generics, keyof, utility types, mapped and conditional types, classes, enums, tsconfig, React and Node with Zod, common errors and a type quiz, with Hinglish explanations.
- Pages
- 26
- Format
- A4 PDF
- Language
- English + Hinglish
- Price
- Free by email
What's inside
24 topics, one page each
- 01What TypeScript is, type erasure and structural typing
- 02Basic types, tuples, any vs unknown vs never
- 03Type inference, literal types and as const
- 04Function types, optional params and overloads
- 05type vs interface, readonly, index signatures
- 06Unions, intersections and the 5 ways to narrow
- 07Discriminated unions and exhaustive checks
- 08Type guards, assertion functions and satisfies
- 09Generics, constraints and defaults
- 10keyof, typeof and indexed access types
- 11Utility types: Partial, Pick, Omit, Record, ReturnType and more
- 12Mapped types and key remapping
- 13Conditional types, infer and distribution
- 14Template literal types
- 15Classes: modifiers, parameter properties, abstract, #private
- 16Enums vs union types and as const objects
- 17import type, declaration files and @types
- 18tsconfig and what strict mode turns on
- 19TypeScript with React: props, hooks and events
- 20Runtime validation with Zod in Node APIs
- 21Common TypeScript errors and how to fix them
- 22Interview questions with short answers
- 23"What's the type?" quiz
- 24Revision cheat sheet
TypeScript questions now come up in most frontend and full-stack interviews. These notes explain the type system one idea per page, with short examples you can paste into the TypeScript Playground and check by hovering.
What makes these TypeScript notes different?
- Answers to the classic questions. any vs unknown, type vs interface, private vs #private, enums vs unions and annotation vs
asvssatisfies, each with a clear rule. - The type system, step by step. From narrowing and discriminated unions to generics, utility types, mapped types and conditional types with
infer. - Real project use. tsconfig strict mode, React props and events, and runtime validation with Zod, because types disappear at runtime.
- A quiz and an error guide. Predict the type of 14 snippets, and fix the 8 compiler errors you'll see most.
How should you use these TypeScript notes?
Paste each example into the TypeScript Playground and hover the variables to see the inferred types. Try writing Partial, Pick and ReturnType yourself after reading the mapped and conditional type pages. Use the quiz and the last page as revision before the interview.
This is Part 14 of the series. For the JavaScript underneath, see the JavaScript handwritten notes.
FAQ
Questions about these notes
Are these TypeScript notes really free?
Yes. The full 26-page PDF is free; email me to request the complete PDF. Share it with friends preparing for placements.
Do I need to know JavaScript first?
Yes, the basics. TypeScript is JavaScript plus types, so the notes focus on the type system. The JavaScript handwritten notes (Part 1) cover the language itself.
Do the notes cover advanced types like generics and conditional types?
Yes. Generics, keyof and indexed access, every common utility type, mapped types with key remapping, conditional types with infer, distribution and template literal types, each with short examples.
Is TypeScript with React covered?
Yes. Typing props and children, useState and useRef with generics, reducers with discriminated unions, form and change events, and extending native element props.
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