In this chapter, we have covered some of the history around JavaScript, and specifically the series of fortunate events around JavaScript's ecosystem that have cemented the language as the most important programming language in recent history. We can now not only write client-side code for execution in the browser, but we can write JavaScript code that runs on the server. As if this wasn't a compelling enough reason to use more JavaScript than what you may have used in the past, you can also use JavaScript for native mobile development, and for creating desktop applications as well. It's quite an exciting story!
We then took a low fly-by look at the additions to JavaScript that were added with the release of ES6. These additions were quite substantial, especially since JavaScript had remained largely unchanged for over a decade, and have really strengthened the language as a result. We also enumerated some of the benefits that TypeScript brings to the table. Remember that you can view TypeScript as being a superset of JavaScript, and you can define it as ES6 plus optional typing.
Microsoft's contribution of TypeScript to JavaScript developers was one of the most important things the company has contributed to the open source world in a long time. Angular itself was written in TypeScript, due to the advantages TypeScript has over pure JavaScript, and so when building Angular applications, it's best to use TypeScript to write them. We've remembered that JavaScript is the only language that can be executed in the browser, but fortunately, TypeScript ships with a transpiler to turn our TypeScript code into pure JavaScript code.
As mentioned in the roadmap, chapter 3 Bootstrap – Responsive Grid Layout and Components, we have a similar goal. In this chapter we will do a crash course on SASS, which is what we'll be using to style our Angular components instead of using CSS. We'll also cover enough of Bootstrap to get you comfortable with using the venerable CSS framework to lay out our web pages for ListingCarousel, the web application we'll be building together. You'll gain enough knowledge to immediately apply these skills to virtually any web application project you may currently have or soon be starting on in the future.