This tutorial was tested with Node.js version 14.3.0 and npm version 6.14.5. Both Node and npm (or yarn) installed in order to run a development environment that handles TypeScript-related packages.To set this up on your local machine, you will need the following. PrerequisitesĪn environment in which you can execute TypeScript programs to follow along with the examples.

You will try out different code samples, which you can follow in your own TypeScript environment or the TypeScript Playground, an online environment that allows you to write TypeScript directly in the browser. In this tutorial, you will create interfaces in TypeScript, learn how to use them, and understand the differences between normal types and interfaces. They allow you to make the usage of those structures type-safe and document them simultaneously, directly improving the developer experience. Interfaces in TypeScript are a powerful way to represent type structures. You can also use types to create aliases of primitive types (such as string and boolean), which interfaces cannot do. The main difference is that interfaces may have more than one declaration for the same interface, which TypeScript will merge, while types can only be declared once. You may notice that interfaces and types share a similar set of features in fact, one can almost always replace the other. (For more about types, check out How to Use Basic Types in TypeScript and How to Create Custom Types in TypeScript.) Interfaces in TypeScript have two usage scenarios: you can create a contract that classes must follow, such as the members that those classes must implement, and you can also represent types in your application, just like the normal type declaration. TypeScript offers multiple ways to represent objects in your code, one of which is using interfaces.

TypeScript is an extension of the JavaScript language that uses JavaScript’s runtime with a compile-time type checker. The author selected the COVID-19 Relief Fund to receive a donation as part of the Write for DOnations program.

Typescript includes