Understanding Function Overloading in TypeScript

Have you ever found yourself needing to write a function in TypeScript that can handle different types of input parameters?

AI powered modern mona lisa

Function overloading is a powerful feature that can help you accomplish just that. Function overloading is a feature in TypeScript (and many other programming languages) that allows you to define multiple functions with the same name but different parameter types and/or return types. This can be really useful when you want to write functions that can handle different types of input parameters.

Let’s look at an example to see how function overloading works in TypeScript. Suppose we want to write a function that takes two numbers and returns their sum. We could write it like this:

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

This function works great when we want to add two numbers together. But what if we want to add two strings together instead? We could modify the function like this:

function add(a: number | string, b: number | string): number | string {
 if (typeof a === "number" && typeof b === "number") {
  return a + b
 } else if (typeof a === "string" && typeof b === "string") {
  return a + b
 } else {
  throw new Error("Invalid…