Book Image

Mastering TypeScript 3 - Third Edition

By : Nathan Rozentals
Book Image

Mastering TypeScript 3 - Third Edition

By: Nathan Rozentals

Overview of this book

TypeScript is both a language and a set of tools to generate JavaScript. It was designed by Anders Hejlsberg at Microsoft to help developers write enterprise-scale JavaScript. Starting with an introduction to the TypeScript language, before moving on to basic concepts, each section builds on previous knowledge in an incremental and easy-to-understand way. Advanced and powerful language features are all covered, including asynchronous programming techniques, decorators, and generics. This book explores many modern JavaScript and TypeScript frameworks side by side in order for the reader to learn their respective strengths and weaknesses. It will also thoroughly explore unit and integration testing for each framework. Best-of-breed applications utilize well-known design patterns in order to be scalable, maintainable, and testable. This book explores some of these object-oriented techniques and patterns, and shows real-world implementations. By the end of the book, you will have built a comprehensive, end-to-end web application to show how TypeScript language features, design patterns, and industry best practices can be brought together in a real-world scenario.
Table of Contents (16 chapters)
Free Chapter
TypeScript Tools and Framework Options


An interface provides us with a mechanism to define what properties and methods an object must implement, and is, therefore, a way of defining a custom type. We have already explored the TypeScript syntax for strongly typing a variable to one of the basic types, such as a string or number. Using this syntax, we can also strongly type a variable to be of a custom type, or more correctly, an interface type. This means that the variable must have the same properties as described in the interface. If an object adheres to an interface, it is said that the object implements the interface. Interfaces are defined by using the interface keyword.

To illustrate the concept of interfaces, consider the following code:

interface IComplexType { 
    id: number; 
    name: string; 

We start with an interface named IComplexType that has an id and a name property. The id property...