TypeScript: Complete Course from Zero
Master TypeScript from basic types to advanced generics, decorators, and real-world patterns. Build a fully typed REST API client with authentication, error handling, and reusable utility types.
Course Content
6 modules · 30 lessonsTypeScript Foundations
Set up TypeScript and write your first typed code with confidence.
What is TypeScript and why use it over JavaScript
TypeScript definition, static typing, compile-time errors, JavaScript superset, type safety benefits, tooling advantages
How to install TypeScript and compile your first file
Node.js requirement, npm install typescript, tsc command, tsconfig.json basics, compiling ts to js, running output
TypeScript primitive types: string, number, boolean, null, undefined
string type, number type, boolean type, null type, undefined type, type annotation syntax, implicit vs explicit types
TypeScript arrays and tuples explained with examples
array type syntax, generic array syntax, readonly arrays, tuple definition, tuple use cases, tuple vs array
TypeScript any, unknown, and never types when to use each
any type risks, unknown type safe alternative, never type unreachable code, type narrowing with unknown, exhaustive checks with never
Object Types and Interfaces
Model complex data structures with interfaces and object types that keep large codebases consistent.
How to type objects in TypeScript with inline types
object type annotation, property types, optional properties, excess property checking, object literal types, readonly properties
TypeScript interfaces vs type aliases what is the difference
interface declaration, type alias declaration, extending interfaces, intersection types, declaration merging, when to use each
How to extend and implement interfaces in TypeScript
extends keyword for interfaces, multiple inheritance, implements keyword, class interface contracts, interface composition
Index signatures and dynamic object keys in TypeScript
index signature syntax, string index signatures, number index signatures, mixed known and dynamic keys, Record utility type
Intersection types in TypeScript combining multiple types
intersection type syntax, combining interfaces, merging type properties, conflict behavior, practical composition patterns
Functions and Type Narrowing
Write fully typed functions and use narrowing to handle union types safely in real code.
How to type function parameters and return types in TypeScript
parameter type annotations, return type annotations, void return type, optional parameters, default parameters, rest parameters
Function overloads in TypeScript how and when to use them
overload signatures, implementation signature, overload resolution, when overloads are necessary, practical overload examples
Union types and type narrowing in TypeScript
union type syntax, typeof narrowing, instanceof narrowing, in operator narrowing, narrowing pitfalls, control flow analysis
Type guards and custom type predicates in TypeScript
type predicate syntax, is keyword, user-defined type guards, discriminated unions, type assertion vs type guard
Higher-order functions and function types in TypeScript
function type syntax, arrow function types, callbacks, returning functions, type inference with higher-order functions, Function type pitfall
Generics
Write flexible, reusable code that stays fully type-safe across any data type using TypeScript generics.
What are generics in TypeScript and why do you need them
generic type parameter, identity function, type parameter naming, generic vs any, generic inference, basic syntax
Generic constraints in TypeScript using extends
extends constraint, constraining to interface, keyof constraint, multiple constraints, why unconstrained generics fail
Generic interfaces and generic classes in TypeScript
generic interface declaration, generic class, generic stack implementation, multiple type parameters, default type parameters
Built-in TypeScript utility types Partial, Required, Readonly, Pick, Omit
Partial type, Required type, Readonly type, Pick type, Omit type, practical use cases for each, combining utility types
Generic utility types ReturnType, Parameters, and Awaited explained
ReturnType utility, Parameters utility, Awaited utility, infer keyword introduction, extracting types from existing functions
Classes and Object-Oriented TypeScript
Use TypeScript classes with access modifiers, decorators, and design patterns for production-grade OOP code.
TypeScript class basics access modifiers public private protected
class declaration, constructor syntax, public modifier, private modifier, protected modifier, readonly modifier, parameter properties
Abstract classes and inheritance in TypeScript
abstract class, abstract method, extends for classes, super keyword, method overriding, when to use abstract vs interface
Static members and singleton pattern in TypeScript
static properties, static methods, class-level vs instance-level, static blocks, singleton pattern implementation
Getters and setters in TypeScript classes
get accessor, set accessor, computed properties, validation in setters, backing fields, accessor vs method
TypeScript decorators introduction class and method decorators
decorator syntax, class decorators, method decorators, decorator factories, enabling experimentalDecorators, practical logging decorator
Advanced Types and Real-World Patterns
Use conditional types, mapped types, and template literals to write expert-level TypeScript that scales.
Mapped types in TypeScript transforming existing types
mapped type syntax, keyof in mapped types, as clause remapping, built-in mapped types internals, removing modifiers, conditional mapped types
Conditional types in TypeScript ternary logic at the type level
conditional type syntax, extends in conditional types, infer keyword, distributive conditional types, NonNullable explained
Template literal types in TypeScript dynamic string types
template literal type syntax, string interpolation in types, Capitalize Uppercase built-ins, combining with unions, event name patterns
TypeScript module augmentation and declaration merging
declaration merging for modules, augmenting third-party types, ambient modules, global augmentation, .d.ts files basics
TypeScript project configuration strict mode and performance tips
strict mode flags breakdown, noUncheckedIndexedAccess, paths aliases, project references, skipLibCheck, incremental compilation