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


Generics are a way of writing code that will deal with any type of object, but still maintain the object type integrity. So far, we have used interfaces, classes, and TypeScript's basic types to ensure strongly typed (and less error-prone) code in our samples. But what happens if a block of code needs to work with any type of object?

As an example, suppose we wanted to write some code that could iterate over an array of objects and return a concatenation of their values. So, given a list of numbers, say [1,2,3], it should return the string 1,2,3. Or, given a list of strings, say [first,second,third], return the string first,second,third. We could write some code that accepted values of type any, but this might introduce bugs in our code—remember S.F.I.A.T.? We want to ensure that all elements of the array are of the same type. This is where generics come in...