TS>JS (For Scaling)

Before this class, I had heard of Angular before and had always heard it referred to as a JavaScript framework. I guess technically it is, because it still compiles to JavaScript but the language itself is written in the JavaScript superset, TypeScript. I had never heard of TypeScript before this class and the idea of a superset language was also a new concept. I was curious why Angular was written in TypeScript over JavaScript or other supersets. I know from outside sources that the first iteration of Angular was written in JavaScript but every iteration of the framework since, has been written in TypeScript and I wanted to know why. This post by Victor Savkin lays out the benefits of using TypeScript as a way of explaining why Google chose TypeScript for Angular.

Victor clears up my lack of understanding of what a superset is relatively simply. He explains that being a superset of JavaScript, everything you can do in JavaScript, you can do in TypeScript. With small changes to the code, a “.js” file can be renamed a “.ts” file and compile properly.

Victor emphasizes the lack of scalability in vanilla JavaScript. With JavaScript, large projects are much more difficult to manage for many reasons including the weakly typed aspect and the lack of interfaces. TypeScript solves these problems and helps create better organized code with its syntax. With its better organization, TypeScript is much easier to read through compared to JavaScript.

The lack of interfaces in JavaScript is a major reason why it doesn’t scale well for large projects. Victor uses a code example in JavaScript that shows that aspects of a class can be lost in JavaScript because of its lack of explicitly typed interfaces. The code is then reshown in TypeScript and is much more clear because you can actually see the interface. It’s that simple, in JavaScript, you have to really focus in on how every object interacts with each other because of the lack of explicitly typed interfaces. TypeScript allows you to create these interfaces so future code maintenance is less stressful and bug filled.

TypeScript offers explicit declarations, which is illustrated through some code samples in the article. The JavaScript code is a simple function signature that lacks any typing or clear information about the variables involved in the function. In the TypeScript version, it is clear what the types of the variables are, making the function much more clear in TypeScript.

There are other reasons defined in this article on why TypeScript was chosen and what makes it so great, but these are a few of the ones that stuck out to me. I’ve written JavaScript projects before and wondered how some of these concepts would affect larger projects, and now I know how they can be resolved. This article and information will prove useful for writing my final project and any future TypeScript-based projects that I decide to take on in the future.

Original Post: https://vsavkin.com/writing-angular-2-in-typescript-1fa77c78d8e8

 

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