Which Type of Language is JavaScript?

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JavaScript Course With Certification: Unlocking the Power of JavaScript
JavaScript Course With Certification: Unlocking the Power of JavaScript
by Mrinal Bhattacharya
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JavaScript Course With Certification: Unlocking the Power of JavaScript
JavaScript Course With Certification: Unlocking the Power of JavaScript
by Mrinal Bhattacharya
Start Learning

JavaScript commonly referred as JS is one of the core technologies used in the World Wide Web. It is a text-based, object-oriented programming language used to make web pages and apps more dynamic and interactive for visitors.

What is JavaScript?

JavaScript is a lightweight, interpreted, or just in time compiled language that conforms to ECMAScript standards. JavaScript is used to add interactivity to websites and make them appealing to users, create complex web applications, etc. Initially, it was used as a scripting language but over the years it is been used in many non-browser environments such as Node JS which enables us to use JavaScript outside of the browser.

JavaScript is a high-level language

A High-Level Language (HLL) is a programming language that enables the development of a program in a user-friendly manner and is generally independent of the computer's hardware architecture. High Level Languages are easier to read, the code in HLL is then translated to machine language by a compiler or interpreter. Some examples of High Level languages are: JavaScript, C++, Python. JavaScript is an HLL because it has great flexibility (using functions as objects) and provides a lot of different data structures to work with without worrying about how they work internally.

JavaScript is a weakly typed language

A weakly typed language is a language that makes conversions between unrelated types implicitly. This means that the language decides to convert the data type of the variable to another data type. This sometimes can be helpful but can also lead to unexpected results. Let's understand this better with the help of an example:


Here JavaScript automatically converted num which was int to a string

Client Side JavaScript

In modern websites, two major components are involved:

  • Client
  • Server

Client is the end-user who is accessing the website and Server is the one who serves or provides the client with the requested information.

Client JavaScript refers to the JavaScript that is used on the client's end. What it does is, it enables enhancements and manipulation of web pages on the client's browser.

How does it work?

The script that needs to run is referenced by the HTML document. So HTML calls this script and it works to make the webpage dynamic.

Some examples to make things clear:

  • Suppose there is a button on a website that displays some image when clicked. With JavaScipt you can add a container that will display when the button is clicked. But without JavaScript, you have to refresh the page to get the image.
  • When you fill a form, mostly they instantly tell you if there is some kind of error. This is called form validation and this is also a function of JavaScript because you can check the field without refreshing the page.

So, whenever you want to perform some task, but don't want to refresh the page, you take the help of client-side javascript.

Advantages of JavaScript

  1. Interactivity JavaScript increases the interactivity of the websites by dynamically adding styles, and performing tasks like form validation without refreshing the page.
  2. Less server load JavaScript decreases the load on servers, like in the case of forms, the input is validated before sending to servers, so the server has to do less work.
  3. Immediate Feedback JavaScript gives immediate feedback to the users as users don't have to wait for the page to reload.
  4. Rich Interfaces JavaScript enables developers to create complex interfaces like drag-n-drop, modals, etc.
  5. Integration JavaScript works well with many programming languages, so it makes it easy to integrate into a host of different applications.

Limitations of JavaScript

As with all things, JavaScript also has some limitations.

  • Cannot read or write files on the client-side(for security reasons).
  • No multiprocessor/multi-threading capabilities.
  • Due to lack of support it cannot be used for networking applications
  • Behaviour of JavaScript varies from browser to browser.
  • Not SEO friendly
  • It can be disabled in the browser
  • Cannot use local devices.

JavaScript development Tools

JavaScript does not require you to have expensive development tools to work with. Since it is a scripting language so you can use a simple text editor like Notepad to write code. JavaScipt in the context of browser is interpreted so there is no need for a compiler. The entry barrier is very low.

Some of the tools preferred by developers are:

  • Visual Studio Code (VSCode)
  • Atom
  • Sublime Text
  • CodePen
  • Notepad++

What is JavaScript used for?

Initially, JavaScript was used only for creating websites, but with the development of Node which is a runtime that allows us to use JavaScript outside of the browser, JavaScript has found several applications in almost every field.

  • Creating Interactive Web pages This article explains how JavaScript is used to make interactive web pages that appeal to the user.
  • Building Applications JavaScript is used to create applications for mobile, desktop, and web. Some frameworks provide a blueprint for developers to create these applications.
    • React/Vue/Angular - used for making web applications
    • React Native - used for making mobile applications
    • Electron - used for making desktop applications
    • Node.js - used in servers
  • Making Games JavaScript is the first choice of developers when it comes to making browser-based games.

Learn more

To learn more about JavaScript you can visit our article on What is JavaScript?


After reading this article you can now answer the question What is JavaScript. Here is a quick rundown of the main points:

  • JavaScript is lightweight, interpreted, or just-in-time compiled language.
  • It is a High-Level Language (HLL)
  • It is a weakly typed language
  • JavaScript can be used on both Client and Server-side
  • JavaScript enables us to create interactive web applications and rich web interfaces.
  • Javascript has a low entry barrier and can be written with just simple text editors.
  • JavaScript is also used outside the browser to build web, desktop, and mobile applications.
  • Some limitations of JavaScript include non SEO friendly, no file access on the client-side, lack of multithreading, etc.