TypeScript vs JavaScript: Differences and Similarities

By Darrel Carpenter on 03.31.21   /   Web Development   /   Leave a comment

JavaScript has received high praise because of its powerful features to enhance website interaction. It’s also the most used scripting language for many web development projects and has been in existence for over 20 years.

TypeScript can be described as a type of JavaScript with a set of additional features. In this JavaScript vs TypeScript article, we compare the differences and similarities of these two languages.

• What is JavaScript?
• What is TypeScript?
• Why JavaScript?
• Why TypeScript?
• Difference between JavaScript and TypeScript
• History of JavaScript
• History of TypeScript
• Features of JavaScript
• Features of TypeScript
• JavaScript vs TypeScript: Which is better?

Ok, let’s dig in.

1. What is JavaScript?

JavaScript is a popular programming language which helps you create dynamic web pages. It’s mostly used on the client-side and it runs in the web browser without the need of any resources from the web server.

The scripts are embedded within web pages and automatically executed when the page loads. Because the script is provided in simple text, it does not need any special compilations. And this feature makes JavaScript relatively fast. However, JavaScript was designed for applications containing a few 100 lines of code. It is not designed for large, complex applications.

Although JavaScript is well-known as a scripting language for web pages, it’s also used in many non-browser environments. This includes use in Adobe Acrobat, Node.js and Apache CouchDB.

2. What is TypeScript?

As stated early on in this article, TypeScript is a superset of JavaScript. What we didn’t say is that TypeScript provides features such as classes, generics, interfaces , and static typing. By catching mistakes early through its type system, TypeScript makes JavaScript development more efficient. When IDEs are enabled, it provides a more thoughtfully designed area for spotting common errors as you type the code.

To put it differently, TypeScript is a modern age JavaScript programming language.

3. Why JavaScript?

• Its use has now extended to mobile app development, desktop app development, and game development.
• Can be used in both front-end and back-end of web development.
• Ideal for small size project.
• Compiled JavaScript runs in any browser.
• Open source project with Microsoft funding.
• Supports modules, classes and interfaces.
• JavaScript can be extended for writing large apps.

4. Why TypeScript?

• It is a superset of JavaScript.
• TypeScript implies JavaScript making it easier to code, read and debug.
• It’s a powerful type system including generics.
• Most of the commonly used libraries are supported with Type Definitions.
• Easier refactoring.
• TypeScript code can be converted into plain JavaScript code.
• It allows developers to focus on exposed API rather than having to know all the code by heart.

5. Difference Between JavaScript and TypeScript

Following is the main difference between JavaScript and TypeScript:

JavaScript	TypeScript
A scripting language for developing dynamic web pages	A JavaScript superset for tackling large code projects through collaboration
In interpreted languages, therefore, it is possible to find errors during run time	Errors can be discovered and corrected during compilations
No option for static typing; weakly typed	Supports both static and dynamic typing, strongly typed
Used directly in browsers	Converted into JavaScript before use in browsers
JS libraries work by default	All JS libraries and code works without any changes since its a superset
Does not support compilation of any of the ES features	TS supports all ES features
It does not support modules, generics, and interfaces	Supports module, generics, and interface for data definition
The feature for functions to have optional parameters is not available	Functions can have optional parameters
Example code:function sum (x, y) { return x+y;}var result = sum(20, 35);console.log(`adding x and y we get ` + result);	Example code:
Numbers and strings are classified as objects	Numbers and strings are considered to be interfaces
It does not support creating prototypes	Supports forming prototypes
No primary scripting language is needed and can be learned right on the go!	Scripting knowledge is a prerequisite and takes time to learn how to code

6. History of Javascript

JavaScript was originally called Moncha. It was developed by programmer Brendan Eich of Netscape Communications Corporation and launched on September 1995. In 1996, Netscape present JavaScript to the European Computer Manufacturers Association (ECMA) as the best scripting tool.

7. History of Typescript

Microsoft developed Typescript and also maintained it under the Apache 2 license. It was developed by a programmer Andres Hejlsberg and introduced for use in October 2012. In 2013, a new version of Typescript was developed by Microsoft- TypeScript 0.9. The latest stable version is TypeScript 3.4.5, which was released in April 2019.

8. Features of JavaScript

• Low reloading speed
• Great for communication with a server
• It’s easy for beginner programmers to learn
• Used for client-side and server-side
• Excellent cross-platform language
• You can do just about whatever you want with any object

9. Features of TypeScript

• Scalable HTML5 client-side development
• Code navigation and bug prevention
• Supports classes, subclasses, interfaces, and sub-interfaces
• Offers great productivity for developers
• Maintainability
• Rich IDE available with autocomplete and code navigation feature

10. JavaScript vs TypeScript: Which is better?

While JavaScript has been available since 1995, TypeScript has gained momentum. To conclude this TypeScript vs JavaScript differences article, we can summarize like this. JavaScript is more conducive to small coding projects. And for large projects where team collaboration is needed, TypeScript would be the better solution.

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