Typescript Generics Development Tutorials, Guides & Insights

function identity<T>(arg: T): T {
  return arg;
}

const result = identity<string>("Hello TypeScript");

You can constrain generics to ensure that the types passed to them meet certain requirements. This is useful when you want to make sure that the generic type has certain properties or methods.

function identity<T>(arg: T): T {
  return arg;
}

const num = identity<number>(42); // T is replaced with number
const str = identity<string>('Hello'); // T is replaced with string

In this example, T is a type variable that allows the identity function to accept and return any type.

TypeScript allows you to add type annotations to variables, function parameters, and return types:

let isDone: boolean = false;
let count: number = 10;
let name: string = "Alice";

function add(a: number, b: number): number {
  return a + b;
}