JavaScript vs TypeScript

JavaScript

JavaScript, since its first appearance in 1995, built its reputation as an ideal scripting language for web pages. Over the years it has gained rave reviews for visual representations too. Great supportive frameworks like AngularJS, ReactJS, Ember.js etc. have provided JavaScript with much-needed flexibility. The language's increasing popularity in the last few years is powered with a helpful community monitoring its efficient use.

JavaScript is comparatively more flexible in development time. It allows time in validating that a certain object can be used in a particular way. Here's another benefit, for example, consider a before-after scenario and a single website page with a header, footer, text box, images and a sidebar. Earlier, the entire page needed to be uploaded to make any changes. But now, if sidebar elements need reworking, developers do it without overhauling the entire set up. Today's UI/UX design, drop down boxes, search boxes can be intricately and competently set up with CSS and JavaScript.

TypeScript

TypeScript is a free and open source programming language developed and maintained by Microsoft. Since 2012, TypeScript is a superset of JavaScript which primarily provides optional static typing, classes and interfaces. An existing JavaScript program can also be a TypeScript program. One of the big benefits is to enable IDEs to provide a richer environment for spotting common errors as you type the code. Experts like Anders Hejlsberg have mentioned how Typescript is about scaling JavaScript for making it easier to build medium to large applications.

TypeScript brings in a whole lot in extending JavaScript capabilities with static typing. Developers can make use of static typing, whenever the need arises. Static typing's purpose is to eradicate the development errors, much before code execution. Imposed restrictions on interacting with objects, forces developers to clearly specify things. A type has to be clearly defined, apart from other parameters that make up the method. As a result, tooling enables the developer to detect the error much before the application is run.

JavaScript vs TypeScript

1. The ECMAScript - ECMAScript is the standardized specification for the JavaScript language. It's sometimes referred as ECMAScript Harmony or ES.next. At the time of this writing, JavaScript is currently at ECMAScript 5. A few browsers implement some of the ES6 specification, but adoption is increasing daily. TypeScript edges ahead in its ability on allowing developers use a major part of the latest version of ECMAScript features. The language thus makes up for the resource gap developers always had.
2. Error detection - TypeScript doesn't take away JavaScript's dynamic capabilities, it just allows developers to make effective use of the static typing approach. Static typing sends out the error signals early. It helps developers in discovering which objects work and don't work. Tooling enables developers to spot their errors and correct them a good deal before the application is run, a total contrast to JavaScript's real-time trail and error approach.
3. Large App Capabilities - JavaScript wasn't meant for large applications or say, thousand-odd lines of code. Today we have code lines running to millions and beyond. This is where TypeScript budged in with its large app capabilities.
4. A Faster JavaScript - JavaScript framework wasn't written in TypeScript. You can simply write down the Type definitions for it. The integrated development environment (IDE) then validates it for you. Making changes in the browser and reloading is also faster in TypeScript, with a set of tools. TypeScript is in many ways, JavaScript in fast forward mode.
5. Safer Refactoring - Refactoring in TypeScript is 'safer', as we are armed with a semantic knowledge of the code. This was not possible in JavaScript. In fact, more the lines of code you write in JavaScript, the more fragile it becomes.
6. Code Prompting in TypeScript - TypeScript is evolving as a language service for JavaScript. Using a TypeScript declaration file, for example, for procuring information and getting code prompts on functions,arrays, methods, etc is one of its uses. TypeScript can thus eventually serve as a consistent help center and instant code correction module for a JavaScript file.
7. TypeScript Code is converted into JS Code - TypeScript code is not understandable by the browsers. That's why if the code is written in TypeScript then it is compiled and converted the code into JavaScript.
8. Different approach - TypeScript is known as Object-oriented programming language whereas JavaScript is a scripting language. TypeScript has a feature known as Static typing but JavaScript does not have this feature.
9. Static type - TypeScript has a feature which is strongly-typed or supports static typing. That means Static typing allows for checking type correctness at compile time. This is not available in JavaScript.
10. TypeScript cross-platform - TypeScript code can be run on any browser, devices or in any operating system. TypeScript is not specific to any Virtual-machine etc.
11. Data Binding - TypeScript uses concepts like types and interfaces to describe data being used. On the other side, no such concept is available with JavaScript.
12. Prototyping - Typescript has a feature of prototyping. And JavaScript doesn't have this feature.
13. Light/Heavy-weight - Typescript is a heavy weighted. an interpreted programming language. JavaScript is a light weighted and it's specially designed for development of large application and trans compile to JavaScript.
14. Flexibility - Some developers prefer the flexibility of JavaScript. Others, however, prefer the less-flexible TypeScript as its compiler produces cleaner code.
15. Use case - JavaScript is used in development for enhancing HTML pages in an interactive and design fashion. It used, particularly in client side. But Typescript may be used to develop a JavaScript application for both client-side and server- side. It is designed for development of a large application that trans compile to JavaScript.
16. IDE support - The development experience with TypeScript is a great improvement over JavaScript. The IDE is informed in real-time by the TypeScript compiler on its rich type information. This gives a couple of major advantages. With TypeScript, you can safely do refactorings like renames across your entire codebase. Through code completion, you can get inline help on whatever functions a library might offer. No more need to remember them or look them up online references. Compilation errors are reported directly in the IDE with a red squiggly line while you are busy coding. All in all, this allows for a significant gain in productivity compared to working with JavaScript. One can spend more time coding and less time debugging. There is a wide range of IDEs that have excellent support for TypeScript, like Visual Studio Code, WebStorm, Atom, and Sublime.
    

When you should use TypeScript instate of JavaScript?

• When you have a large codebase
• When your team's developers are already accustom to statically-typed languages
• When a libraries or framework recommends TypeScript
• When you really feel the need for speed in development process