Functions are the basic building block of any application, whether they’re local functions, imported from another module, or methods on a class. They’re also values, and just like other values, …

TypeScript has a specific syntax for typing function parameters and return values. Read more about functions here.

Jul 23, 2025 · Writing a function in TypeScript is similar to writing it in JavaScript but with added parameters and return type. Note that any JavaScript function is a perfectly valid TypeScript …

In TypeScript, we can specify a function that can be called in different ways by writing overload signatures. To do this, write some number of function signatures (usually two or more), …

A function expression is a way to store functions in variables. In this tutorial, you'll learn about TypeScript functions and function expressions with the help of examples.

While TypeScript provides the concept of classes and modules, functions still are an integral part of the language. In TypeScript, functions can be of two types: named and anonymous.

Learning TypeScript's Functions chapter shows how a function's parameters and return types can be inferred or explicitly declared in TypeScript:

In this TypeScript tutorial we learn how to group sections of our code into smaller, reusable units, with functions. We learn how to define and invoke functions, how to add parameters and …

In this tutorial, you will learn about the TypeScript functions and how to use type annotations to enforce the type checks for functions.

In the following example, the function add receives two numbers and returns a number. The function defines the types of the parameters and its return value using the : operator. …