Introduction To JavaScript

by Keith Dvorjak

JavaScript is known as the "language of the web" because it is used in the development of an incredibly high number of applications on the web and the mobile paradigm alike. It is the language that makes web applications dynamic so that users can interact with them, which provides a rich user experience. When JavaScript came into existence around 1995, most of the logical calculations and input validations in web pages were primarily done using server-side languages like PHP. The process was very long and unnecessarily involved two-way trips, first to send a request to the server and then get the data/error back to the client's computer. It was a huge letdown to UX. The need of that time was to make validations right on the client's computer before sending to the server, thereby reducing the bandwidth, which at that time was a major issue so that the user would not have to wait just to see if he made any errors while typing out that form.

JavaScript was created by Brendan Eich as “LiveScript” in 1995, which got renamed to “JavaScript.” It was initially named “Mocha” but then named JavaScript to gain traction with the language Java that was getting popular at the same time. The first major standardization occurred in the form of ECMA standardization. The first version developed still lacked features like REGEX and JSON and some important built-in functions.

The language kept getting developed and adding features to its repertoire. It was the ECMA v3 that saw the birth of AJAX (Asynchronous JavaScript and XML), which today is at the core of every web application and framework. At present, the language is packed with exciting new features.

Let’s look at the advantages one gets with JavaScript:

• JavaScript is a lightweight, interpreted programming language.

• Designed for creating simple as well as complex web applications.

• Furthers the functionality of web pages.

• Animations and Visual effects can be done easily.

• UX/UI improvements.

Owing to the language’s success and usability, many frameworks and libraries like jQuery, Angular JS, React JS has been developed which makes writing code in JavaScript a delight. JavaScript is the scripting language that is being actively used by developers around the globe in creating interactive web applications that are visually appealing and at the same time packed with functionalities just like desktop applications are.

It means that web pages are not static in nature. The elements can be modified and made interactive, functional, and animated by the use of this language as a scripting tool.

this language as a scripting tool. JavaScript began as a client-side scripting language but is being used on the backend side of the web also in the form of Node.js. Many libraries and frameworks have sprung up in the meantime to make the developer’s life easy. JavaScript has built-in as well as user-defined methods/functions that allow themselves to get bound to certain buttons or elements and can be called whenever and wherever. These functions are being actively used to automate tasks like the setTimeout() or setInterval() functions that can be called after a certain period of time to do some task.JavaScript can be used in the HTML file itself, if it is written into the tags, and can also be attached to it as an external file. The extension of a JavaScript program is ‘.js.'

JavaScript is often abbreviated as JS. Some of the main features of the language are as follows:

• High-level, Weakly-Typed.

• Interpreted.

• Functional.

• Object-Oriented

Object-Oriented design is perhaps the most important feature of JavaScript, as it allows us the creation of objects and establishes relationships between them, commonly known as Inheritance and Encapsulation.