What is TypeScript?: Why it Matters, and How it's Transforming Web Development

(If you are not a beginner in .Net programming, you can leave this and directly jump to Starting with TypeScript.)

Preface: Well techies, in this article I am just going to tell you about Microsoft's new product TypeScript. But before starting about TypeScript, I would like to say something about the .Net revolution and how Microsoft is providing the best tools and languages to build applications.

Microsoft has delivered many IDEs, tools and new Languages to develop software solutions. Now in Visual Studio 2012, Microsoft has come out with a new language "TypeScript". In Visual Studio 2012 there are not many changes other than tools, templates, looks and feel so you can continue with it without migration hassles from older versions.

Microsoft provides a smarter and easier way of developing software solutions/applications with modular approaches. You can notice that Windows 8 is totally changed from earlier Windows. The new Team Foundation Server (TFS) is providing much more and making life easier for group programming/coding. Metro Style applications are a hit. I read an article somewhere and the writer was saying that it is the end of Microsoft by launching its Windows 8. Surprise!!! Probably he forgets to mention that it was Microsoft who developed the highly GUI based Windows Operating System and made computers usable for common people. How many common people use other operating systems than Microsoft Windows? At that time too it was a very big change from the current trend too. I personally see it as a new evolution because common people are accustomed to common functionalities (in modern life everyone is using mobile, at least those who will be using the new Microsoft Windows 8) so in a few days they will be found easier to work with the new look and feel with the functionality of Microsoft Windows 8.

First, let me say that if you are thinking to be proficient in TypeScript then it is a good choice and makes the development of large-scale web applications easier and smarter. I coded in the days of Visual Basic 6.0 and now we can see the market demand is web and web applications. For a while there we saw some forward developments toward Windows Desktop based applications using WPF and Silverlight but not web.

Since this article is about TypeScript, so I am not going to go into a deep history or bore you with my childhood stories. But we see two major changes since the first launch of the .Net framework 2002. Now, .Net is a decade old and has gone through Web services to WCF services, from SOAP messages to RIA. Now almost everyone is looking for web-based applications. Most web applications are being developed in WCF and the MVC pattern. It has gone to small development companies now. Bigger companies are mixing the technologies and working with WPF and Silverlight, wiring them with WCF services and building large-scale web applications.

A few days ago one of my technical architect friends switched from a pure MVC pattern based ASP.Net to the WPF side. He says there is a lot to go and come in that version of .Net. He also adds that big changes can be noticed in current Windows applications and earlier versions of Windows applications. In fact, web development has overtaken the race from Windows version development but the later is giving a good challenge now.

Anyway, you came to this article to learn something about TypeScript, so I will proceed to take you on that show.

Well, every web application is enhancing its behavior, look and feels, and animations or say delivering more responsive applications with the help of JavaScript and CSS.

JavaScript has become the main choice for nearly all web developers and has become popular in them. These web experts were missing some advanced features like Interface, Class, Inheritance, explicit type cast, reflection, object array support, etc. in JavaScript.

There are many plugins written in JavaScript and being utilized under various licensing types. So it is no doubt that JavaScript has been accepted as a very important part of web application development. And the interesting thing is that today's famous jQuery and other frameworks/libraries are well written in JavaScript only.

It has been very hard to write complex & long code in JavaScript since JavaScript allows us to delay until the last moment (run) and finally it breaks due to some mistakes.

Then you need to investigate the deepest and lengthiest code of JavaScript. The thing is, it doesn't have annotations, and type-safe validations, etc. and allows you to write until it goes in action. Complex object data type creation, constructors, interface creation, modularization are the main concern when writing scripts in JavaScript.

To overcome the above problem, a new Language has been designed and built on the base platform of JavaScript. So the purpose was clear to build this new language as it was that just fill the gap of missing features into JavaScript. And this new language is intended to allow us to write our scripts in real-world objects (complex ones), use of interfaces, constructors and type-safe at the moment of code typing and much more. Its code fault detection during coding is a boost and saves a significant amount of time. It also has annotations to help us while writing scripts. TypeScript is just for that. It is not like C# and VB.Net that compiles its code into MSIL; instead, it compiles into pure JavaScript!!!

Picture: TypeScript is based on ECMAScript and is a super-set of JavaScript with high-level language features.

So we can just say that TypeScript is a language that is a superset of JavaScript but a subset in syntax. It has been designed to make the building of large-scale web applications easier with its features like modules, interfaces, classes, etc. If you don't mind (I am not sure, sorry) I would like to abstract it as a very high-level special translation tool that has most of the features of any high-level language. TypeScript was born from JavaScript and finally converts into JavaScript.