Do You Know What Is JavaScript? Know More About The Salient Features, History and Its Future.


HTML, CSS, and Javascript are the core technologies of the World Wide Web. Now the main question arises. What is Javascript? What is Javascript used for?

Javascript is a high-level programming language that is used widely in the modern web. It is a client-side as well as a server-side language. It has a vast amount of features like dynamic programming, prototype-based object-orientation, and first-class functions. The majority of the web sites in the modern world are developed using javascript and the major web browsers use the javascript engine to execute it. Javascript helps in creating interactive web pages. It supports event-driven, functional, object-oriented, and prototype-based programming styles. Javascript greatly helps in DOM manipulation. It has flexible APIs for working with a variety of data types like strings, dates, arrays, regular expressions, etc. The syntax of javascript is also very simple and easy to learn. But don’t mistake javascript for java. Although, their names sound similar and their syntax is also quite similar, but they greatly differ in design.

Many famous javascript frameworks like AngularJS are used for developing single-page websites. Powerful Javascript libraries like ReactJS are useful while developing not only single page websites, but mobile applications also. Javascript has an important part in modern web development.

History of Javascript

It was realized that the web needed to be more dynamic and the future web should have animations, interactions, and other automation. It could all be done by DOM interaction and for DOM interaction, a scripting language was needed. But java was on the rise at that time. This new scripting language does not need to target big-shot developers. The web was purely static at that time. HTML was also young at that time and it didn’t need big-shot developers. So the people at Netscape decided, a simple scripting language can be helpful for making the web dynamic that even the non-developers could use. Then, the idea of Mocha was born.

The sun technologies were contacted by Netscape to cut a deal to make java available in the browser. But java at the time was the only popular high-level language and needed well-skilled and experienced developers. Netscape wanted to target designers, scripters, and people with no experience of programming. Mocha was ideal for it. A simple scripting language for web and a companion of java. This is when Netscape hired Brendan Eich, also known as the father of javascript. Eich had the freedom to do what he likes but there was a lot of pressure on him. Other languages like python were also the candidates. He had to design a prototype as soon as possible. Eich started working on it and mocha’s first prototype was introduced in the Netscape communicator in 1995. Later that year, the deal between sun and Netscape closed and mocha(also called LiveScript) was renamed to Javascript. At that time, javascript was only presented as a scripting language meant only for scripting work, while the java was the original language for heavy and rich web development.

Features of Javascript

The following are the features of javascript.

DOM Manipulation

The following is an example of using javascript for DOM manipulation.



<button onclick=”demoFunction()”>click</button>

<p id=”para1"></p>


function demoFunction()


document.getElementById(“para1”).innerHTML = “Hello World!”;





In the body tag, there is one button tag used to create a button. Javascript is used to handle the button click event and when the button is clicked, “Hello world!” appear below it. This is DOM manipulation using javascript. Observe the code in the script tag. Inside the demoFunction, the getElementById method is used to access the id of a paragraph tag below. This is how “Hello world!” is added to the DOM dynamically.

Functions as First-Class Objects

function function1(x) {



function function2(var1, callback) {



function2(2, function1);

In the above code, function1 along with value is passed as an argument in function2. In the function2, function1, now as callback, is used. This is how functions are passed in javascript.

Javascript as a Client-Side Language

Platform Independent

The Syntax is Similar to Java

Date and Time

Prototype-Based Object Model

The following code shows the use of prototypes in javascript.

function Employee(firstName, secondName, age, employeeNumber) {

this.firstName = firstName;

this.lastName = lastName;

this.age = age;

this.employeeNumber = employeeNumberl


Person.prototype.nationality = “English”;

Form Validation

Detecting the User’s Browser and OS

Ability to Create Functions in the Script



<button onclick=”demo()”>Click</button>

<p id=”para1"></p>



function demo(){

document.getElementById(“para1”).innerHTML = Hello world




The above HTML code has a script where a function is used.

Javascript Frameworks and Libraries

Let us check some of the Javascript libraries and frameworks.


Check this guide on the top AngularJS frameworks.



Advantages of Javascript

  • Javascript provides dynamic programming that is heavily used in the modern web.
  • When used as a client-side language, Javascript is very fast as it runs immediately in the browser.
  • One does not need to master different languages for the client-side and server-side.
  • The javascript frameworks and libraries had made web development easy and straight-forward.
  • Javascript is very simple to learn as compared to other programming languages like java. Being one of the core technologies of the World Wide Web, resources for javascript are easily available online and offline.
  • Regardless of the file extension, We can insert javascript in any web page.
  • Javascript supports all modern web browsers.
  • Javascript provides extended functionalities to the web pages.
  • No compiler is needed in javascript.
  • Javascript is an event-based programming language.

Limitations of Javascript

  • One of the biggest limitations of javascript is that the code is visible to everyone.
  • Javascript as the client-side does not allow the reading and writing of files.
  • There are no multithreading capabilities of javascript.
  • Javascript cannot be used for networking applications.
  • It can be disabled.


Javascript is often described as the most disliked language. It was poorly designed. But it was not intended to be what it is today. From just a server-side language under the shadow of java to one of the core web technologies of the World Wide Web, javascript has covered a long distance. It is used as server-side as well as client-side. Features of javascript are useful, yet complicated. Many languages came and diminished but javascript is still here and it will remain here for a long time, probably forever.

Originally published at Acodez .

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