Javascript for Web Development: An Introduction

There was a time when websites were primarily built using basic HTML and CSS which provided static content with minimal interactivity. Fast forward to today and we find ourselves in an era where JavaScript frameworks and libraries have taken web development to the next level. Today developers can create complex applications more efficiently than ever before.

JavaScript has made web development much easier and if you are a seasoned web developer, you can’t imagine building websites without Javascript. Its real-time manipulation of the Document Object Model (DOM) enables developers to create responsive interfaces that react instantly to user actions.

In this detailed blog on JavaScript, we will look at how JavaScript is used in modern web development. So let’s get started.

What is JavaScript

JavaScript is just a programming language, but the beauty is that you can use it for frontend development, server-side development, mobile app development, and many other possibilities.

It all started as a basic scripting language that allowed you to manipulate HTML and CSS programmatically. Today, you can use it to build almost all kinds of software applications. HTML and CSS allow you to create the layouts and styles for your website while JavaScript brings them to life. You can control what actions to take when a user scrolls, hovers, or interacts with any part of your application.

One major advantage of JavaScript is that you don’t need to install any files to start working with it. You can run your program directly inside your browser. And not just that, if you want to run your code on your system, you can install Node.js or Bun.js, which provides a runtime environment for JavaScript. In browsers, we have the V8 engine, which allows you to compile and run your application.

The syntax of JavaScript is one of the most intuitive and straightforward syntaxes. For example, if you want to create a simple calculator, the code is shown in the above image.

Why do we use JavaScript for Web Development?

Without JavaScript your favourite shopping platform, OTT platform or social media platform, everything will no longer be user-friendly. JavaScript helps you build web applications that are interactive, dynamic, and responsive. Even a small interaction like adding items to a cart, or liking a social media post, JavaScript brings these experiences to life. It can make websites more easy to use.

Let’s explore its role across three major layers of the web development stack:

Front end development

 Every web application that you are using will be using JavaScript on the client side. JavaScript allows you to add client-side features like form validation, image carousals and dynamic content updates without reloading the page. Various 2D and 3D libraries allow you to simplify your workflow. For example, you can try Chart.js to draw 2D charts, graphs etc. and Three.js for creating 3D graphics and animations.

Several front-end libraries can also reduce the amount of work. For example, libraries like React.js can reduce the amount of work that you have to put in when using Vanilla JavaScript.

Backend development

 After Node.js came into existence, JavsScript developers did not need to depend on browsers for running their JavaScript code. They can directly run your code on your system. Thanks to these runtimes. Node.js and Deno are the most popular JavaScript runtimes.

Node.js, Bun.js or any other frameworks like Express.js allow you to write your server-side logic in the backend. You can handle HTTP requests, interact with databases and even build scalable backend systems using JavaScript.

This way you can use the same language on the frontend and backend allowing you to improve the overall developer experience. There are several backend frameworks apart from express, like Hono, EelysiaJS etc.

Fullstack development

 As we mentioned JavaScript can do great at both frontend and backend. This has resulted in a rise in the popularity of full-stack JavaScript frameworks like Next.js. Frameworks like Next.js allow you to handle server-side rendering to client-side interactivity. All this makes JavaScript an all-encompassing tool for building modern web apps.

You can also frameworks like React Native for building mobile applications using JavaScript.  With React Native you can build fully native mobile applications enabling cross-platform development for both iOS and Android.

What kind of Language is JavaScript?

Let’s now answer a fundamental question: which type of language is JavaScript?

When we talk about languages like C or Java we know they are strictly typed languages. Strictly typed languages are those languages that have strong type definitions like int, char, string etc.  In JavaScript, we don’t have to explicitly mention the type as it is a loosely typed language. The type of a variable is determined at runtime rather than at compile time.

JavaScript is also a multi-paradigm language meaning that it supports various programming styles which allows you to use the best approach depending on the need.

Imperative Programming

You can think of imperative programming as the step-by-step instruction to get a desired result. The programmer explicitly tells the computer what steps to take.

Functional Programming

JavaScript allows functions to be treated as first-class citizens and enables functional programming techniques. This means that functions in JavaScript can be assigned to variables and can be passed as arguments as well as returned from other functions just like any other data type.

Object-Oriented Programming

JavaScript supports object-oriented principles. Object-oriented programming (OOP) is a paradigm that structures code around objects which encapsulate both data and behaviour. Objects are a foundational part of JavaScript and you can use them to model real-world entities with properties (data) and methods (behaviour)

Asynchronous programming

 Apart from the other paradigms, JavaScript is known for its ability to handle asynchronous code. It allows you to have non-blocking operations and enables the execution of tasks concurrently rather than sequentially.

JavaScript is a single-threaded language. It can execute only one command at a time. In an ideal scenario, we would want to perform other processes in parallel. JavaScript uses the event loop to manage asynchronous operations.  Instead of waiting for time-consuming tasks like fetching data from an API or reading files, JavaScript can delegate these tasks to the browser or runtime environment. This allows the main program to continue running while the asynchronous task is being processed in the background.

The above code is a callback function and it will only be executed after two seconds but it does not halt the program.

Getting Started with JavaScript

Let’s now look at some of the basic concepts in JavaScript.

Variables and Data Types

 In JavaScript, there are mainly 3 ways to declare variables: let const and var.

• Let: Let allows block scope variable declarations which means the variable is only accessible within the block it was defined.
• Const: const is used to declare variables whose value should not be reassigned after their initial assignment. Const also has a block scope.
• Var: Var has functional scope and it is the traditional way of declaring variables.

Javascript has several built-in data types: They are divided into primitive and non-primitive data types. Examples of Primitive datatypes are String, Number, Boolean, BigInt etc. An example of a Non-primitive data type is Objects.

Functions

Functions are the blocks of code for performing a specific task. It can take arguments as inputs and return the output

Objects in JavaScript

Objects are the most fundamental concept in JavaScript. You can say that almost everything in JavaScript is an object.  An object consists of properties and methods.

Once you are confident in JavaScript, you can start learning Typescript. Static typing can help you prevent numerous bugs and scaling problems in large codebases. TypeScript adds static typing to JavaScript. It can enhance your development experience by allowing for early error detection during compile time rather than runtime. TypeScript also improves code readability and maintainability.

Keep in mind that while there are many JavaScript frameworks, they will come and go. Don’t feel pressured to chase every trend. Focus on building a strong foundation. Since JavaScript has a huge ecosystem, if you ever get stuck, you can rely on developer forums like Stack Overflow or other helpful sites

Conclusion

Thanks for checking out this blog. In this detailed post on JavaScript, we’ve discussed everything you need to know before getting started. We covered various important concepts in JavaScript like functions, objects, data types, and more.

These foundational concepts will enable you to write effective JavaScript code and build dynamic web applications. Learning JavaScript is a no-brainer because there are countless opportunities for JavaScript developers. As you learn more, you’ll realize the possibilities with JavaScript are endless.

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