Javascript - Features

---

---

JavaScript Features

JavaScript is a highly popular and widely-used programming language for web development. It has a variety of features that make it powerful and flexible. Some of these features include being dynamic, lightweight, interpreted, functional, and object-oriented.

Many open-source JavaScript libraries are available, facilitating the utilization of JavaScript in both frontend as well as backend development. Let's highlight some of the key features of JavaScript.

Easy Setup

We don’t need a particular editor to start writing the JavaScript code. Even anyone can write JavaScript code in NotePad. Also, JavaScript can be executed in the browser without any interpreter or compiler setup.

You can use the <script > tag to add JavaScript in the HTML file. However, it also allows you to add JavaScript to the web page from the external JavaScript file, having '.js' extension.

Browser Support

All browsers support JavaScript, as all modern browser comes with the built-in JavaScript execution environment.

However, you can also use the ‘window’ object to check whether the browser supports JavaScript or its particular feature.

Dom Manipulation

JavaScript allows developers to manipulate the webpage elements. Also, you can control the browser.

It contains the various methods to access the DOM elements using different attributes and allows to customize the HTML elements.

Event Handling

JavaScript allows you to handle the events used to interact with the web page.

For example, you can detect the mouse click on a particular HTML element using JavaScript and interact with the HTML element.

Some other events also exist, like detecting the scrolling behavior of web page, etc. We will explore all events in the ‘JavaScript events’ chapter.

Dynamic Typing

JavaScript decides the type of variables at runtime. So, we don’t need to care about variable data type while writing the code, providing more flexibility to write code.

Also, you can assign the values of the different data types to a single variable. For example, if you have stored the number value of a particular variable, you can update the variable’s value with the string.

Functional Programming

JavaScript supports the functional programming. In JavaScript, you can define the first-class function, pure functions, closures, higher-order functions, arrow funcitons, function expresions, etc.

It mostly uses the functions as a primary building blocks to solve the problem.

Cross-platform Support

Each operating system and browser support JavaScript. So, it is widely used for developing websites, mobile applications, games, desktop applications, etc.

Object-oriented Programming

JavaScript contains the classes, and we can implement all object-oriented programming concepts using its functionality.

It also supports inheritance, abstraction, polymorphism, encapsulation, etc, concepts of Object-oriented programming.

Built-in Objects

JavaScript contains built-in objects like Math and Date. We can use a Math object to perform mathematical operations and a Date object to manipulate the date easily.

However, you can also manipulate the functionality of the built-in object.

Object Prototypes

In JavaScript, everything is an object. For example, array, function, number, string, boolean, set, map, etc. are objects.

Each object contains the prototype property, which is hidden. You can use the prototype property to achive inheritance or extend the functionality of class or object, by other object’s functionality.

Global Object

JavaScript contains the global object to access the variables which are available everywhere.

To access global variables in the browser, you can use the window object, and in Node.js, you can use the 'global' keyword to access global variables.

Recently, globalThis keyword is introduced to access the global variables, and which is supported by the most runtime environments.

Built-in Methods

JavaScript also contains the built-in methods for each object. Developers can use the built-in methods to write efficient and shorter codes.

For example, the Array object contains the filter() method to filter array elements and the sort() method to sort the array. The String object contains the replace() method to replace text in the string, the trim() method to remove whitespaces from the string, etc.

Modular Programming

JavaScript allows you to write the code in different modules and connect them with the parent module. So developers can write maintainable code.

By writing the code in a separate module, you can reduce the complexity of the code and reuse each module whenever you require.

JSON

JSON stands for JavaScript object notation. It is a widely used data format to exchange data between two networks. For example, server and client.

JavaScript also supports the JSON format to store the data.

Asynchronous Programming

JavaScript is a single-threaded programming language. To execute your code faster, you can use asynchronous programming.

You can use promises in JavaScript to write asynchronous code, allowing us to handle multiple tasks asynchronously.

Even-driven Architecture

The event-driven architecture of JavaScript allows developers to create interactive and responsive web applications by handling a large user base concurrently.

Due to the vast features and applications of JavaScript, the front end of Facebook is built on JavaScript. Netflix is built using the ReactJS framework of JavaScript. Similarly, Amazon, PayPal, Airbnb, LinkedIn, Twitter, etc., are also built using JavaScript.

Server-side Support

The Node.js runtime environment of JavaScript is widely used to create the backend of the application, as javaScript can also be used to create servers. It allows you to create a scalable backend for the application.