TypeScript vs JavaScript: What’s the Difference?

If you are a web developer, you would know that JavaScript is the ‘king’ of web development. Even if you have just entered the web development world, you’d have realized how crucial the role of JavaScript is, in building websites.

JavaScript is a highly popular programming language (scripting language to be precise) that has been in the market for over two and a half decades. The popularity of JavaScript can be witnessed by the fact that more than 97% of websites on the Internet use JavaScript on the client-side for web page behavior.

Read: Choosing the Best JavaScript Framework Between Vue and React

The market cannot exist without competition. Be it anything, there would always be an alternative available for it or would step in after some time. For JavaScript, that alternative is TypeScript.

TypeScript is an open-source programming language that is used to build complex and large-scale applications. In fact, handling large-scale applications was the core reason behind its development. The language was developed in 2012 by Microsoft. TypeScript is considered to be an enhanced version of JavaScript with some additional features.

Several frameworks including the likes of Angular leverage TypeScript for web development services. Although JavaScript is the primary choice for building web apps, it isn’t quite suitable for creating large and complex web applications. That’s where TypeScript comes into play.

You might be wondering what’s the difference between JavaScript and TypeScript. Are they both the same? Which is better between the two? In today’s blog post on “JavaScript vs TypeScript”, we will compare the two programming languages, see how they relate to each other, and how they differ.

TypeScript vs JavaScript: Are they the same?

Every JavaScript code is valid in TypeScript, the same can’t be said for the TypeScript code. In other words, JavaScript is a subset of TypeScript. When we add more features to JavaScript, the result is TypeScript. If you save your JavaScript file (.js) with a TypeScript (.ts) extension, it will work absolutely fine, however, that doesn’t imply that both the languages are the same.

Reason Behind the Birth of TypeScript

When JavaScript was introduced, it was primarily supposed to be a client-side programming language. With time, developers realized that it could also be used as a server-side programming language. However, this made the JavaScript code quite heavy and complex. It couldn’t really stand up to the expectations of an object-oriented programming language. JavaScript never actually succeeded as a server-side technology, and hence TypeScript was born to bridge that gap. TypeScript serves the same purpose as JavaScript and can be used for both the client-side and server-side. Additionally, JavaScript libraries also show compatibility with TypeScript.

TypeScript supports both static and dynamic typing. It offers a multitude of features like classes, namespaces, visibility scopes, unions, interfaces, inheritance, and more. In addition to these, it offers comments, variables, expressions, functions, modules, and statements. It can be executed on Node.js or browsers that display compatibility with ECMA Script 3 or its latest versions.

As TypeScript is what you may call an upgraded or enhanced version of JavaScript, the entire JavaScript code is syntactically valid TypeScript.

Features of TypeScript

1. TypeScript supports JS libraries, platform-independency, object-oriented programming concepts, and several other JavaScript features.

2. TypeScript shows compatibility with all JavaScript versions like ES7 and ES12.

3. Supports Static Typing which helps you with early bug detection, quick code completion, and more.

4. TypeScript isn’t specific to any single environment. It can be compiled to run on any device, OS, or browser.

5. Easy to maintain.

6. Helps boost developer productivity.

About JavaScript

JavaScript is a scripting language that is used to build interactive web pages. Together with HTML and CSS, JavaScript is a fundamental part of the World Wide Web. The majority of websites on the Internet use JS for client-side web page behavior, and all major browsers have a dedicated JavaScript engine to perform it. JavaScript can be used with other technologies like XML and REST APIs. The programming language follows the ECMAScript arrangement. It supports dynamic typing and encompasses curly-bracket syntax, first-class function, and prototype-based object orientation.

Features of JavaScript

1. JavaScript is flexible and powerful

2. It is cross-platform

3. Receives support from almost all browsers

4. Easy to learn and start with

5. Strong testing workflow

JavaScript vs TypeScript: Which is better?

Let us break down the differences between JavaScript and TypeScript based on the following factors-

1. Syntax

Unlike TypeScript, JavaScript doesn’t offer variable declaration, functional paradigm, and type system. In terms of syntax, TypeScript is similar to JavaScript with support for ECMAScript 2015 standard features which include classes, modules, and an arrow function syntax. It’s not that JS doesn’t follow the ECMAScript definition, however, it isn’t a typed language like TypeScript. It utilizes structured programming terminologies from C, like switch statements, do-while statements, if statements, etc.

2. Performance

Since TypeScript was developed to tackle the challenges associated with JavaScript for large and complex applications, it has an edge over JavaScript in terms of performance. It saves an ample amount of time and makes web development more efficient. The only thing to note here is that the TypeScript code is compiled into JavaScript before execution.

3.  Tools and Frameworks

JavaScript has many frameworks such as Angular, React, and Vue.js that help developers with multiple aspects of web development. It’s a huge ecosystem.

Read: React vs Angular: Which is Better and Why?

Speaking of TypeScript, it contains several leading frameworks and editors, also because it is backed by one of the tech giants, Microsoft. Its integration with editors helps in error handling during compilation to avoid errors at runtime.

4. Learning Curve

Since TypeScript is a superset of JavaScript, you must be well-versed with the latter to grasp the former. In other words, you should have prior scripting knowledge. In addition to this, you should also have a clear understanding of the OOPS concept.

JavaScript is a very popular language that is used by web developers all around the world. It is flexible and an easy-to-learn scripting language- comparatively easier than TypeScript.

Advantages of TypeScript over JavaScript

1. TypeScript identifies compilation errors at the time of development, which reduces the possibility of runtime errors.

2. As TypeScript supports static typing, it allows checking for type correctness at compile time. You do not get such a feature in JavaScript.

3. Typescript offers better code-structuring object-oriented programming techniques.

TypeScript vs JavaScript: When should You Use What?

1. JavaScript is ideal for small and medium-sized projects with fewer lines of code. On the other hand, TypeScript would be a better choice for large projects or when several developers are working together.

2. Some frameworks do not yet support TypeScript. If TypeScript doesn’t get the support for your choice of framework, you won’t be able to make the most of its features. On the other hand, you can use existing JavaScript frameworks and libraries to develop web applications relatively faster and streamline web development.

3. Using JavaScript without the assistance of build tools is popular.

4. If you are starting a completely new project that uses the React framework, and aren’t accustomed to its API, then consider using TypeScript. With the help of IntelliSense, you can navigate through and ascertain novel interfaces.

Final Thoughts

Both JavaScript and TypeScript are excellent in their own ways. JavaScript is the go-to language for the front-end of web pages and apps. TypeScript can also be used for the same reason but it also caters to the backend. In other words, it is suitable for both front-end and back-end.

To understand the difference between JavaScript and TypeScript, in a nutshell, the former is a scripting language whereas the latter is an object-oriented programming language. TypeScript comes with Interfaces and modules while JavaScript doesn’t provide any such feature.

If you are thinking if TypeScript will replace JavaScript, the answer is NO. TypeScript may inherit the basic nature of JavaScript but it is a totally different language.

Still confused as to what you should choose. Don’t worry. Get in touch with our expert web developers and they will help you pick the right technology based on your project requirements.