Generics Development Tutorials, Guides & Insights

To get the most out of this tutorial, you should have a basic understanding of TypeScript, including how to define types, interfaces, and basic generics. If you're new to these concepts, consider reviewing them before diving into this tutorial.

TypeScript allows you to define complex types using type aliases and interfaces. While both serve similar purposes, type aliases are generally more flexible and can be used to create union types, intersection types, and more.

If no type is provided, T defaults to string.

TypeScript provides several advanced types that allow you to describe complex type transformations and constraints.

type Readonly<T> = {
  readonly [K in keyof T]: T[K];
};

interface Car {
  make: string;
  model: string;
  year: number;
}

const myCar: Readonly<Car> = {
  make: 'Toyota',
  model: 'Corolla',
  year: 2020
};

// myCar.make = 'Honda'; // error

type IsString<T> = T extends string ? 'string' : 'not string';

type Test1 = IsString<string>; // 'string'
type Test2 = IsString<number>; // 'not string'