The book can be divided in two sections. The first section, chapters 1 to 4, describe how you can build standard application. These chapters introduce Angular 2 and React for web applications, NodeJS for servers and NativeScript for mobile apps. You should read chapters 1 to 3 in a sequence.

The second section, chapters 5 to 8, introduce more complex concepts. You will learn functional programming in chapters 5 to 7. The last chapter contains guidance to migrate a JavaScript codebase to TypeScript. You can read chapters 5 to 7 when you have not read chapters 1 to 4, though chapter 5 requires some knowledge of React.

Chapter 1, TypeScript 2.0 Fundamentals, will explain core principals to create (web) applications with TypeScript. If you have some basic knowledge of TypeScript 2.0 then you can skim over this chapter or use it as a reference while reading the other chapters. If you have not used TypeScript yet, then this chapter will teach you the fundamentals of TypeScript 2.0

Chapter 2, A Weather Forecast Widget with Angular 2, you will learn how you can build an application in Angular 2. The chapter introduces core principals of Angular and will use an online API as source for the weather forecast.

Chapter 3, Note-Taking App with a Server, we will build a server and client with Node and Angular for this application. You will see how code can be shared between the client and the server.

Chapter 4, Real-Time Chat, introduces React and websockets. Using these techniques, we will write the server and client of the chat application.

Chapter 5, Native QR Scanner App, after having written three web applications, we will now write a mobile app. You will learn how you can use NativeScript and its plugins to write a native app.

Chapter 6, Advanced Programming in TypeScript,  covers more advanced features of TypeScript, including type guards, control flow analysis and performance of algorithms.

Chapter 7, Spreadsheet Applications with Functional Programming, introduces a different programming style: functional programming. You will learn how this can be used in TypeScript. We will use React with a Flux-based architecture, which fits nicely with TypeScript and Functional Programming.

Chapter 8, Pac Man in HTML5, will show how to use the HTML5 canvas to create a game. We will use some Functional Programming again, and take a look at how we can create a framework for it based on the Flux architecture.

Chapter 9, Playing Tic-Tac-Toe against an AI, will explain how to build a command-line application in which you can play Tic-Tac-Toe. You will learn how you can learn the computer to play the game. When done correctly, the computer should never lose.

Chapter 10, Migrate JavaScript to TypeScript, will show how you can incrementally migrate a JavaScript codebase to TypeScript. We will focus on how you can keep the project working during this transition.

You will need an editor to write the code, a terminal to compile the code, and a browser to see the results. Visual Studio Code and Atom with atom-typescript are good editors in which you can write TypeScript code. These are available for Windows, Mac, and Linux. You have to compile TypeScript in a terminal. On Windows, you can use the Command Prompt or Powershell for that. On a Mac, you can use Terminal.

To compile TypeScript, you need NodeJS. You can find details on how you can install it in the first chapter.

Chapter 5, Native QR Scanner App, has more requirements to run the mobile app in an emulator or a device. Details about how you can install these dependencies are found in the chapter.

If you are interested in building fun projects using TypeScript, then this book is for you. This book will appeal to web developers who wish to make the most of TypeScript. You should be familiar with the fundamentals of JavaScript.

In this book, you will find a number of text styles that distinguish between different kinds of information. Here are some examples of these styles and an explanation of their meaning.

Code words in text, database table names, folder names, filenames, file extensions, pathnames, dummy URLs, user input, and Twitter handles are shown as follows: "We can include other contexts through the use of the include directive."

A block of code is set as follows:

export function factorial(x: number): number {
   if (x <= 1) return 1;
   return x * factorial(x - 1);
}

When we wish to draw your attention to a particular part of a code block, the relevant lines or items are set in bold:

export function factorial(x: number): number {
   if (x <= 1) return 1;
   return x * factorial(x - 1);
}

Any command-line input or output is written as follows:

npm init -y

New terms and important words are shown in bold. 

Feedback from our readers is always welcome. Let us know what you think about this book—what you liked or disliked. Reader feedback is important for us as it helps us develop titles that you will really get the most out of.

To send us general feedback, simply e-mail [email protected], and mention the book's title in the subject of your message.

If there is a topic that you have expertise in and you are interested in either writing or contributing to a book, see our author guide at www.packtpub.com/authors.

Now that you are the proud owner of a Packt book, we have a number of things to help you to get the most from your purchase.