Functions

Functions in TypeScript

TypeScript lets you annotate both parameter types and the return type.

Basic function

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

Arrow functions

const multiply = (a: number, b: number): number => a * b;

TypeScript will warn you if you pass the wrong types or return the wrong value.

Optional parameters

Add ? to make a parameter optional:

function greet(name?: string): string {
  return `Hello, ${name ?? 'stranger'}!`;
}

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Your task

Write and export a function named add that:

• Takes two number parameters: a and b
• Returns their sum as a number

export function add(a: number, b: number): number {
  // your code here
}