front matter
preface
This is the 50th book I have written and the third edition of Essential TypeScript. TypeScript was new when I wrote the first edition, and my editor was reluctant to commission the book. I am glad I persisted because digging deep into a technology in its early days provides an excellent foundation for seeing it mature. Over the years, Microsoft has shaped TypeScript into a powerful and robust language that has been widely adopted and which makes JavaScript easer to use for countless developers. Originally associated with Angular, TypeScript is now supported by every major development framework and its approach to enhancing JavaScript has become the gold standard.
But TypeScript isn’t a conventional stand-alone programming language: it is a set of enhancements that are applied to JavaScript. JavaScript is an elegant and expressive language, but it behaves like few other languages, and its unusual approach to data types causes endless confusion. TypeScript doesn’t change the JavaScript type system, it just helps prevent unexpected results, and effective TypeScript development requires a good understanding of JavaScript. This book contains a primer that explains the most confusing JavaScript features so that you have the knowledge you will need to use and appreciate TypeScript.