TypeScript	JavaScript
Multi-paradigm, object-oriented, and generic programming language	A scripting language, event-driven, and functional
Developed by Anders Hejlsberg at Microsoft	Developed by Brenden Eich of Netscape
Extends JavaScript and is used in large-scale application development	The core technology in world wide web and used almost in every website and everywhere
First released in 2012	First released in 1995
Errors can be found and corrected at compile time	Only run-time error handling
Supports dynamic and static typing	No static typing, weakly-typed
Needs to be converted into JavaScript for execution	Directly executable and faster compilation
TypeScript is a superset of JavaScript, supports all JavaScript libraries and programs	Only JavaScript libraries
Define and describe data and shape of objects	Not possible in JavaScript
Supports prototyping	No support available for prototyping
Suitable for large-scale applications that have larger code files and large teams	Suitable for small, simple web applications and small teams
It does require npm or any other package manager	It does not require any setup
Requires scripting knowledge to learn it	Anybody can start learning JavaScript, no prior experience is needed.
Small community compare to JavaScript	JavaScript is a huge ecosystem and has a large community of developers.
Used by: Slack, Bitpanda, Medium, Accenture, CircleCI, and many more	Used by: almost all websites and leading companies that include Microsoft, PayPal, Google, Facebook, Uber, Netflix, Groupon, and many others
File Extension: .tsx or .ts	File extension is .js

Let’s discuss these differences in detail.

• Learning Curve:

We already know what JavaScript is. JavaScript is a dominant language and easy to learn and use. There are a large number of JavaScript developers who are using it along with HTML and CSS to create web apps. It is not easy as HTML as it involves scripting, event handling, interactive behavior of web pages, and animations.

TypeScript, on the other hand, is the superset of JavaScript. You will require basic JavaScript knowledge if you want to work with TypeScript. Apart from that, you will require certain OOPS concepts as it is an object-oriented programming language.

• Community:

TypeScript quickly became popular and adopted by a large number of enterprises. There are many resources available to learn TypeScript and developers easily find support from the TypeScript community. It is not larger compared to the JavaScript community. The current JavaScript ecosystem has many frameworks, libraries, and code practices, making it one of the larger communities in the development world.

• Syntax:

A vast difference you can find here between TypeScript and JavaScript. TypeScript differs from JavaScript in a variable declaration, functional paradigm, and type system. Syntactically, it is very similar to JScript, and .Net with support for features like classes, modules, and an arrow function syntax defined in the ECMAScript 2015 Standard.

JavaScript also conforms to the ECMAScript specification but it is not a typed language like TypeScript. It involves much of the structured programming syntax from C such as if statements, do-while loops, switch statements, and so on. It supports functional, imperative programming, and event-driven style.

• Tools And Frameworks

JavaScript is extensively used in web development and there are many frameworks available for JavaScript. It is a massive ecosystem and very popular among developers. You can easily find developers such as ReactJS developer, VueJS developer, Angular developer, and so on.

As TypeScript backed by Microsoft and the community, it is also supported by leading frameworks and editors. It offers error handling at compile time to avoid mistakes at runtime through tight integration with editors.

• Performance:

We all are familiar with the idea that JavaScript was created to overcome the challenges of JavaScript while developing large applications. TypeScript allows developers to become more efficient and saves a lot of time. TypeScript and JavaScript – both offer almost the same performance level; the only difference is TypeScript code is compiled to JavaScript before execution.

• Typescript vs Javascript Code:

TS requires concise, fewer lines of code than JavaScript. Let’s see one example and how it is different in both these languages.

TypeScript Code:
class Vehicle {
private name: string;
constructor (private name: string) {
this.name = name;
}
name() {
return “I have “ + this.name;
}
}

JavaScript Code:
var Vehicle = (function() {
function Vehicle(vehicleName) {
this.name = vehicleName;
}
Vehicle.prototype.name= function() {
return "I have " + this.name;
}
return Vehicle;
})();


Now, we have seen a comparison, let’s see what the benefits of using TypeScript are.

Why Use TypeScript? What Are The Benefits of TypeScript?

• Faster Error Detection:

TypeScript enables IDEs and the development environment to show errors and warnings as you code. Spotting errors earlier and correcting those will not only save your time but also save you from runtime failures. This is one of the key benefits of using TypeScript in your code.

• Optional Static Typing:

JavaScript is a dynamically typed language. Developers will be not able to recognize errors related to the type differences until runtime. TypeScript wins here with optional static typing, meaning that once a variable is declared, it is allowed to take certain values and it can’t change its type. The compiler gives you alerts for any type-related errors while you code.

• Code Optimization:

TypeScript offers advanced features that improve the quality and readability of the code. Being an object-oriented programming language, it offers Type Annotation, Generics, Intellisense, API Documentation, Namespaces, Interfaces, and so on.

• Enhanced IDE Support:

This makes the developer’s job easier than ever before. The development experience of TypeScript is way better than JavaScript due to several features. First, it lets the developer be informed in real-time of type information. Second, compiler errors are directly seen on the screen in highlighted format. Also, you can safely do refactoring without any hassle in TypeScript.

These all let developers experience major productivity gain compared to JavaScript. When you consider large codebases, TypeScript is great over JavaScript in terms of tooling, integration with editors, and so on.

• JavaScript Compatibility:

Working with JavaScript? Want to migrate to TypeScript? It’s very easy. TypeScript has great interoperability capabilities. You can use popular JavaScript libraries but you require an Npm setup. You can rename your JavaScript file with .ts and it will work. For libraries, you need to check versions because type definitions must match the version of the library you are using.

• Portability And Flexbility:

TypeScript adopts JavaScript and thus, it can run on any environment on which JavaScript runs. It does not require any specific runtime environment or VM. It is supported across browsers, operating systems, and devices. It is a flexible, scalable, and efficient programming language.

What Makes TypeScript Different From JavaScript?

We have seen that it offers more features and it is more advanced than JavaScript. In a nutshell, TypeScript is an object-oriented programming language while JavaScript is a scripting language. Thus, TS supports modules and interfaces through ES6 features while JavaScript does not provide such features.

TypeScript vs JavaScript: When To Use What?

Choose TypeScript When:

• You are working with large projects and cross-functional teams
• You want to save time by compile-time checking and easy debugging
• Use OOP concepts in your programming
• Utilize complete IDE support
• Favor static typing

Choose JavaScript When:

• You are working for a small project and small teams
• Prefer test-driven development
• Avoid added dependencies such as npm in TypeScript
• Want to work with large community and ecosystem
• Choose a fairly simple learning curve

Will TypeScript Replace JavaScript?

The short answer is no.

TypeScript is an entirely different language except that it adopts basic building blocks of JavaScript. It can’t or won’t replace JavaScript. JS is a great language and one of the fundamental technologies in web and mobile development. JavaScript is still the most-admired and most-used language for both, client-side and server-side. It rose to the top over a couple of years and is widely used by enterprises across the world.

On top of the above, TypeScript doesn’t run directly into web browsers. It transcompiles to JavaScript. Since JavaScript runs directly in the web browsers and that’s why it is easier to run and debug. Also, TS is not suitable for all types of projects. Both programming languages have their own set of characteristics.

What Are The Limitations of TypeScript?

TS offers tangible benefits when you want to work with JavaScript for large-scale application development.

It requires little code though, but there is an extra step to convert TypeScript to JavaScript and thus it requires a little longer to compile the code. Plus, when you want to use a third-party library, it requires a definition file and that is a concern sometimes.

Who Is Using TypeScript?

If you are familiar with Angular, then you might know that Angular is a TypeScript-based framework backed by Google.

It is used by many well-known companies such as Slack, Stack, Ionic(framework), NativeScript(framework), Circle CI, Bitpanda, and so on. It is supported by a majority of the editors, tools, and IDEs. Slack has migrated from JavaScript to TypeScript for its desktop app.

“TypeScript was such a boon to our stability and sanity that we started using it for all new code within days of starting the conversion. It’s taken about six months to annotate most of the JavaScript in the desktop app codebase.” – Felix Rieseberg, Slack

TypeScript is loved by developers across the world and we will see more adoption of TS in near future.

TypeScript vs JavaScript: A Quick Summary

Choosing a framework, tool, or technology always depends on the requirement. TypeScript or JavaScript? The choice is subjective and includes various perspectives. JavaScript is ideal if you have a small web project and a team of a few people. It is a great choice for a wide range of purposes as it is one of the core technologies. TypeScript is a great choice when your team is working on a large application and consists of many people. It is easy to maintain, offers code optimization, and improves overall productivity. You should choose it over JavaScript when you want to handle complex projects.

The aim of the article is not only to provide you with a detailed comparison but introduce you to a newer language with fresh perspectives along with a comparison with JavaScript.

We seem a little biased towards TypeScript as it is very popular nowadays and at the same time we also know the potential of JavaScript. We hope that you liked this article and if you find anything missing, you can tell us and add value to the blog via commenting below.