What is JavaScript?


JavaScript is a text-based dynamic programming language used on both server-side and client-side to facilitate the creation of interactive web pages. It is very lightweight and is commonly used as part of web pages.

Where HTML and CSS gives the style and structure to web pages, JavaScript makes web pages interactive which engage the users.

Here are some simple examples of JavaScript you might use in your daily life, such as Google’s search box, or refreshing your Twitter feed.

In simple words, JavaScript adds behavior to web pages. JavaScript is the only language that is native to web browsers.

JavaScript History:

JavaScript was developed by Brendan Eich in 1995. It was originally called LiveScript but was later renamed to JavaScript.

Most new programmers think that Java and JavaScript are the same language. In fact, both are very irrelevant. JavaScript is just a scripting language while Java is a very complex backend programming language.

The syntax of JavaScript is related to the programming language C.

What is JavaScript used for?

JavaScript is primarily used for web browsers and web-based application design. But JavaScript is also used outside the web like in servers, embedded hardware controls, and different software’s. Here are some basic things, where JavaScript is used for:

1.Add the interactive behavior to the web pages:

JavaScript allows its users to interact with the web pages. There are unlimited things you can do with the help of JavaScript code on their web pages, these are some examples:

  • Hide or show information with the click of a button.
  • Change the color of the button when the mouse hovers.
  • Slide through the carousel of images on the web page.
  • Zooming in or out of an image.
  • Display a countdown or timer on a web page.
  • Show 2D / 3D animations.
  • Showing dropdown menu.

2.Build the servers and deploying the applications:

JavaScript allows its users to create web servers and backend infrastructure using Node.js.

3.Creating the Mobile and Web Apps:

Developers can use a variety of JavaScript libraries and frameworks to create mobile and web apps.

The JavaScript Framework is a collection of JavaScript code libraries that provide developers with pre-written code to use for routine programming tasks and features.

Some of the popular JavaScript frameworks include Vue.js, React, Angular and React Native. Many companies have used the “Node.js” JavaScript runtime environment built on Google’s V8 engine.

Examples of some popular web apps have been created using JavaScript such as Uber, PayPal and Netflix.

How to run JavaScript?

JavaScript cannot run automatically, web browsers are responsible for running JavaScript code. When a user requests an HTML page with JavaScript in it, the script is sent to the browser to execute it.

The plus point of using JavaScript is that it runs on all modern web browsers. So, you don’t have to worry if your web page visitor is using Chrome, Internet Explorer or Firefox. JavaScript also runs on any operating system, including Mac, Windows, or Linux.

Tools you need to run JavaScript Code:

To run the code of JS you need a text editor to write your code and a web browser to display the code output. You can use any text editor that suits your taste, such as Visual Studio Code, Atom, Excellent, Notepad ++, or any other one you are comfortable with. You can use any web browser, including Firefox, Internet Explorer, Google Chrome, etc.

Why do programmers prefer to learn JavaScript in other programming languages?

  • Easy to learn.
  • JavaScript is the most popular language.
  • JavaScript is the only language that is native to web browsers.

Pros of JavaScript:

The pros of using JavaScript are:

  • Quick feedback to visitors: The user doesn’t have to wait for a page to reload to see if they forgot to enter something.
  • Low server traffic / interaction: You can verify users input before sending it to the server. It saves the traffic of the server that means less load on the server.
  • Richer Interface: JavaScript also allows you to drag and drop components and sliders to give your web page visitors a big interface.
  • Increased Interactivity: Provides an interface that reacts to users in such a way that when a button is clicked a loading animation will show up on the button until the function is added, or a button changes its color when moves the mouse pointer over the button.

Cons of JavaScript:

We cannot use JavaScript as a whole language. It lacks the following features:

  • JavaScript has no multiprocessor or multi-threading capability.
  • We cannot use JavaScript to create networking apps, as no such support is available.
  • On the client side, JavaScript does not allow reading and writing files.

Bottom Line:

JavaScript is a great technology for creating web apps. It is not very difficult to learn. It plays well with other web technologies like HTML and CSS and can even interact with various plugins like Flash.

See Also
What is ASP.NET
What is Ajax Programming