TypeScript Academy · Lesson

Functions: params, default/optional/rest; return types

Define functions with parameters, defaults, optionals, rest args, and proper return types.

Overview

Goal: Learn to declare functions with parameters, optional and default values, rest arguments, and return types.

Functions declare parameter and return types. Here, greet takes a string and returns a string.

function greet(name: string): string {
  return "Hello " + name;
}

console.log(greet("Ada"));