Guide to JavaScript

If you have heard about HTML and CSS in web development, you should know HTML is about content and structure. CSS generally makes your web pages more interactive and look good. We can build some good pages while combing both - HTML and CSS.

The website will still look somewhat static despite utilizing HTML and CSS. They don’t adapt or respond to what you do. With those two, it’s almost like watching an amazing Seinfeld episode over and over again. Well, it’s fun for a while, but it becomes monotonous.

We all know the modern web is dynamic, not static. The websites you visit or use often offer some personalization and engagement that goes beyond what HTML and CSS themselves can offer.

However, to make your web pages and content alive, we will surely need some outside help. And that’s where the role of JavaScript comes into the picture.

We need JavaScript, which you will find anywhere and everywhere across the Internet.

So, let’s proceed further to understand what JavaScript is and why every industry, developer community, and big enterprise goes crazy over JavaScript.

In addition, we will also explore what JavaScript does and why it’s useful. We will also consider the main reasons for learning the language and focus on why it’s required to learn plain JavaScript first, before libraries and frameworks.

If you are a novice web developer and have never used JavaScript before, get your feet wet with our Introduction to JavaScript guide.

JavaScript is a client-side scripting programming language used to create dynamic web page content. JavaScript is an interpreted, full-fledged programming language that enables dynamic interactivity on websites when applied to an HTML document.

JavaScript is a lightweight, object-oriented programming language used for scripting webpages by several websites. Since its introduction in 1995, it has been used for adding programs to webpages in the Netscape Navigator browser. And it has been widely adopted and used by all other graphical web browsers.

If you spend any time on the Internet doing anything, there’s a perfect chance you are running into things that are written using a language known as JavaScript.

You don’t have to look very hard or dig too deep to find examples of JavaScript. In fact, on many websites, you end up using JavaScript - for instance, Google Maps.

Well, you will find the functionality of JavaScript somewhere behind the scenes that you tend to love.

We can also consider another example – Twitter, and some games you might have played – Cut the Rope.

JavaScript is the real programming language behind every magic you feel or see for these web applications.

We know JavaScript is continuously evolving, and it feels like it’s challenging to keep up sometimes. It’s also incredibly flexible that there are many ways to do the same thing. In addition, understanding programming alone can be challenging at first as it takes time.

Well, this is not the scenario with JavaScript.

Learning JavaScript can also be fun and rewarding. In fact, JavaScript is the first programming language that many developers learn.

You must be wondering why?

JavaScript is the next logical step after learning HTML and CSS. JavaScript helps you provide interactivity and websites, even code applications for the browser, desktop, mobile devices, and more.

Although challenging, JavaScript is one of the most beginner-friendly programming languages out of other languages.

The ECMA-262 Specification defined a standard version of the core JavaScript language.

• JavaScript is a lightweight, interpreted programming language
• Designed for creating network-centric applications
• Complementary to and integrated with Java
• Complementary to and integrated with HTML
• Open and cross-platform

There are also other server-side variants of JavaScript, such as Node JS. This enables you to add more features to your website than merely uploading files (real-time communication between several devices). JavaScript can be connected to the climate objects inside the climate environment (like a web browser) to provide programmatic control over them.

It’s widely known for building web pages, and several non-browser applications also utilize it. In fact, JavaScript supports both client-side and server-side application development. It comes with a set of basic objects such as sequences, date and math and a core set of linguistic structures such as control structures, operators and phrases.

Initially, JavaScript had another name – “LiveScript”. But Java – the name was very popular then, so the creator decided to establish a new language as a “younger brother” of Java would help.

With time, it evolved and turned out to be a fully independent language with its own specification called ECMAScript. Hence, it’s no more related to Java at all.

As a JavaScript developer, I believe JavaScript could be a great choice for your first programming language ever.

However, it’s mainly used for:

• Web Development
• Web Application Development
• Server-Side Application Development using Node JS

In fact, JavaScript is not only limited to these things. Furthermore, you can use it for:

• Mobile Application Development using React Native
• Smartwatch Application Development
• IoT Application Development and Microcontrollers

Hence, JavaScript is called a versatile programming language. It’s very popular that anything new comes in is going to have some kind of JavaScript integration at some point.

High Level: JavaScript supports abstractions, allowing you to avoid the details of the system it’s running on. While comparing JavaScript with other languages like C, it uses a garbage collector to automatically manage memory, allowing you to concentrate on writing code rather than managing memory.

Dynamic: Unlike static programming languages, a dynamic language performs many operations at runtime that a static language performs at compile time. In addition to powerful capabilities like dynamic typing, late binding, reflection, functional programming, object runtime change, closures, and many more, this has both advantages and disadvantages.

Dynamically Typed: Variables do not impose types. You can reassign any type to a variable, like assigning an integer to a variable that stores a string.

Loosely Typed: Unlike strong typing, while providing greater freedom, loosely (or weakly) typed languages do not enforce an object's type, depriving us of type safety and type checking (which TypeScript, which is built on top of JavaScript, offers).

Interpreted: JavaScript is commonly known as an interpreted language, which means that, unlike C, Java, or Go, it does not require a compilation stage before a program can run. For performance reasons, browsers actually compile JavaScript before executing it; nevertheless, this is transparent to you and doesn't need you to take further steps.

Multi-Paradigm: Unlike Java, which requires the usage of object-oriented programming, or C, which requires imperative programming, JavaScript doesn’t enforce any particular programming paradigm. Prototypes, the new (as of ES6) classes syntax, and object-oriented writing techniques can all be used when writing JavaScript. JavaScript can be written in an imperative (like C) or functional programming style, both of which feature first-class functions.

Albeit JavaScript is the popular scripting language for websites, it allows developers to use it for many non-browser environments, like Node.js, Apache CouchDB, and Adobe Acrobat.

Honestly, JavaScript is not as scary as you might think. As we said earlier, it’s a fun and flexible programming language and many software development companies use it for both front-end and back-end development.

In addition, JavaScript is also used for Web development, Mobile app development, and Game development. Actually, it supports machine learning algorithms, along with web servers, robots, and Raspberry Pi. Also, it enables projects in Blockchain, like an Ethereum Blockchain JavaScript API.

If we come up with some examples in which JavaScript has been integrated – consider those applications on your phone or web browser-based game you spend the whole day at.

So, if you think JavaScript is becoming obsolete, then let me break the ice – you are quite far from the truth. Let me share one simple fact: JavaScript remains the only language that seamlessly runs in a web browser even after a quarter of a century.

When JavaScript was invented in 1995, we never knew JavaScript could become the cornerstone of modern web development. And the surprising fact was, it was created in just less than two weeks by Brendan Eich at Netscape headquarters.

Now, in today’s era, we are completely reliant on JavaScript - the interactivity it provides. The applications you use, including Netflix, YouTube, Google Maps, Google Docs, and many more, would not have offered such amazing interactivity and features without JavaScript. Let’s not forget about smartphones, operating systems for computers and smart TVs; they come up with JavaScript interpreters installed.

JavaScript is used as a client-side programming language by 98.3% of all websites. The global developer population is expected to reach 28.7 million people by 2024.

Hence, we can conclude that JavaScript is the most used language in the world.

Furthermore, JavaScript provides some amazing advantages for web development that also make the language more popular and useful.

Proactive Community: JavaScript has one of the largest communities on Stackoverflow. Node JS has been downloaded over a billion times.

Easy to Configure: You don’t need to setup JavaScript in order to access its features and create a development environment. All you need is a browser.

Easy Starter: JavaScript is easy to learn, thanks to its flexibility. It’s the best language for intermediate developers, allowing them to use plugins and code snippets to get an application working.

IDE: You can easily create your code in a file with the .js extension using Integrated Development Environment (IDE) or code editor.

Event-based Programming for Dynamic Content: It offers built-in events like ‘onHover’ and ‘onClick’ to execute a specific set of code by acting upon user interaction on a website.

End-to-End Programming: Since JavaScript supports Node JS – a runtime environment, it allows developers to execute code outside of web browsers and use JavaScript for server-side scripting.

Having said earlier, JavaScript is a scripting programming language. It is used to automate processes that users would have to carry out independently and step-by-step.

Additionally, any modification on the web pages, without JavaScript, you visit would require either manually reloading the page or navigating through the series of static menus to find the content you need.

JavaScript handles a huge amount of work by instructing computer programs like web browsers or web applications to carry out specific tasks. Therefore, dynamic features can be used to “tell” an image to animate itself or to go through a slideshow of pictures, and many more.

JavaScript plays an important role in web functionality; all browsers support JavaScript rendering by default. It means that if you directly write a JavaScript command directly into HTML, the web browser will understand them automatically.

JavaScript is often contained in a .js file or incorporated into a web page. Being a client-side language, the web browser downloads it for processing on your systems; no other software or compilers are required.

JavaScript is widely backed by some popular frameworks that are the backbone of any modern website. JavaScript-driven frameworks allow front-end developers to build interactive and engaging user interfaces easily.

Here, we have listed down some of the popular JavaScript frameworks for web development that you should consider. But before going into details, you should have a basic understanding of which JavaScript framework is right for your front end development project.

Considering the prime objective and goal of your project, you can choose the best JavaScript framework, based on its three different categories:

• Open-Source JavaScript Framework
• Commercial JavaScript Framework
• Lightweight JavaScript Framework

Open-Source JavaScript Framework

Open-source JavaScript frameworks are free for everyone. Hence, they become the prime choice for novice developers who wish to get into the world of JavaScript – web development.

For instance, React and Angular are great examples of this open source. As per Google, starting with open source requires minimal knowledge of JavaScript frameworks. They are very easy to understand and learn. You may also consider TezJS – an open source Jamstack framework for front end development.

Commercial JavaScript Framework

We can consider Bootstrap and Foundation JavaScript frameworks, which are commercially developed. The prime objective of commercial frameworks is to provide numerous features as they are constantly being updated.

Lightweight

Well, you don’t need to have a mastery of an entire programming language to build an application. Sometimes, these types of frameworks are also referred to as “micro frameworks” and are more complex and robust.

However, some of these frameworks offer faster rendering time due to the nature of scalability. They also support cross-browser and cross-platform website compatibility. Vue and jQuery are two popular examples of lightweight frameworks.

Since JavaScript is an open source framework, it has given birth to many other frameworks as well. However, some of them are used to build a website or client-side application, while others are used to integrate JavaScript and web technologies.

Having the same nature, developers can deliver a user-friendly experience by utilizing both -the frontend and backend frameworks.

While talking about front end vs back end JS frameworks, backend development has complex syntax, structure, and technical requirements, whereas front end development deals mostly with CSS, HTML, and JavaScript.

Any JavaScript framework, irrespective of its front end or backend functionality, delivers a better user experience for any type of web application.

Angular, Vue, React, and Ember are the most popular JavaScript frameworks for front end development. They each offer a unique method to build a connection between server-side and client-side processes. In fact, if you are using a JavaScript framework, you may experience some benefits from working on all four at once.

JavaScript library is a set of pre-written code snippets that can be used and reused to execute some common JavaScript functions. Most of the time, developers have to perform the same tasks again and again. Thus, JavaScript libraries and frameworks came into existence.

Developers may now use a code snippet to automate a wide range of repetitive processes, including interactive forms and recurrent animations.

Let’s understand the basic introduction to JavaScript in this technical guide.

Syntax

JavaScript can be implemented using JavaScript statements that are placed within <script>…</script> HTML tags in a web page.

Normally, it’s recommended to put the <script> tag, which contains your JavaScript, within the <head> tags.

The <script> tags notify the browser program to start interpreting all the text between these tags as a script. Hence, a simple syntax of JavaScript will look like this:

There are two important attributes in script tags:

Language: This defines which scripting language you are using. Generally, the value will be javascript. In fact, XHTML – the recent version of HTML has phased out the use of this attribute.

Type: The value of this attribute should be set to "text/javascript" in order to identify the scripting language currently in use.

Now your JavaScript syntax will look something like this:

Let’s print “Hello World” as a basic example to understand JavaScript functionality.

We are adding some optional HTML tags as well to save our JavaScript code from a browser that doesn’t support JavaScript.

“//-->” is used to end comments. Also, “//” is used for comments in JavaScript to prevent a browser from reading the end of the HTML comment as a part of JavaScript code.

Now we need to call a function document.write to convert a string into our HTML document.

This function can be used to write HTML, text, or both.

Let’s write down a code here.

The outcome will be:

Hello World!

Whitespace and Line Breaks

JavaScript doesn’t consider tabs, spaces, and newlines that’s written in JavaScript programs. You can use spaces, tabs, and newlines freely in your program to make your code easy to read and understand.

Optional Semicolons

Just like other languages – C, C++, and Java, a semicolon is generally used in simple statements. However, JavaScript gives you the freedom to not use this semicolon if each of your statements is written in a separate line.

Let’s understand an example without using semicolons.

If you want to use the semicolons, then you have to rewrite the above code in a single line as follows:

Pro Tip: It’s recommended to use semicolons for good coding practice.

Case Sensitivity

JavaScript supports case sensitivity. This means you have to be very careful while writing or declaring keywords, variables, and function names. It must be written with a consistent capitalization of letters.

Writing Time and TIME will have different meanings in JavaScript.

Note: You must be careful while writing variables and function names.

Comments in JavaScript

Comments from C-style and C++ style are supported by JavaScript. Therefore:

• JavaScript ignores text between a // and at the end of a line. It’s considered a comment.
• A text between the characters /* and */ is treated as a comment. This may have multiple lines.
• HTML comment opening sequence <!-- has been recognized by JavaScript. Well, it’s considered a single-line comment, just like the // comment.
• JavaScript doesn’t recognize the HTML closing sequence -->. Hence, it’s written as //-->.

Let’s understand the following example to see how to use comments in JavaScript.

If you are planning to become a dedicated web developer, it is the most obvious reason to learn JavaScript.

Even if you have a basic understanding of JavaScript, it will help you build websites from scratch with its prominent libraries and frameworks. And being proficient in JavaScript is what the world demands in today’s job market.

Now is the time to understand why you should learn JavaScript with its main reasons.

JavaScript Developers are Versatile

JavaScript opens numerous possibilities once you have a thorough understanding of it. It allows you to build a client-side (frontend) application using Angular and a server-side (backend) application using Node.js.

Moreover, it also allows you to develop web, mobile, and desktop applications using React Native, and React JS. Utilizing Electron, you can be a master at Machine Learning as well.

Learning JavaScript can make you a professional front end developer. However, that’s not the only option for your career as a JavaScript expert. Mastering JavaScript also opens the door to full stack development, game app development, information security software engineering, and artificial intelligence.

Demand for JavaScript Experts is High (They’re Well-Paid)

JavaScript is the most popular programming language in the world. Hence, it’s no doubt that every developer is adopting skills in the web development industry to fulfill industry demands.

The report – IT Skills Report 2022 from DevSkiller revealed some interesting facts about current developer hiring trends. Based on their analysis of over 200,000 coding tests in 143 countries, they found that 34.8% of companies testing for junior roles tested for JavaScript developers.

Another report from HackerRank reveals that global demand for JavaScript outweighs the expertise available on the market. And the report states that around 53.6% of developers are saying they need JavaScript skills, yet only 42% of student developers claim they are proficient in the language.

JavaScript is the fifth-most popular language that the web development industry looks for in a web developer, four times more than its nearest competitor.

Not only in demand, but if we talk about pay scale, the average yearly salary of JavaScript developers in the United States is around $103,590 per year.

So, if you are in a dilemma of choosing JavaScript, learn JavaScript without any delay. And then become highly employable.

JavaScript is Beginner-Friendly

JavaScript is the actual reason behind every beginner joining the world of coding when compared with other programming languages.

The finest feature of JavaScript is it is installed on every modern web browser. Developers don’t need to set up any type of development environment to write JavaScript code or execute it.

Another shining feature of JavaScript is that you get instant feedback. This means that you will be able to view immediate outcomes once you write a minimal amount of code. Also, it has huge community support on Stack Overflow.

Once you learn about object-oriented, functional, and imperative styles of programming in JavaScript, you can try your hands on new languages like Java, C++, and Python as well.

If you have decided to learn JavaScript or not, it defines whether you are going to learn “Vanilla” JavaScript or not.

Just JavaScript means Vanilla JavaScript means learning the basic language without any frameworks or libraries.

Let’s dive deeper into this topic.

What is Vanilla JavaScript?

If you are curious about knowing what Vanilla JavaScript is, hold on for a moment. You might have googled this term as well. But you might not have got a satisfactory answer.

All you need to know is Vanilla JavaScript is a term that is referred to the native, standards-based, non-extended version.

Well, there’s no difference between Vanilla JavaScript and JavaScript. It’s just utilizing JavaScript without any libraries and frameworks.

So, now the question comes – is it necessary to learn Vanilla JavaScript? Or should I learn Vanilla JavaScript first? Let’s give you an answer now.

Should You Learn Vanilla JavaScript First?

Suppose you are kickstarting your career journey as a JavaScript developer. In that case, it can be the easiest way to get aware of those times – saving libraries and frameworks we just mentioned earlier – and many ongoing debates for learning plain JavaScript first.

JavaScript frameworks may help you get your job or task done quickly, but only if you understand the concepts behind these frameworks.

Hence, to prove this thing right, our vetted front-end developer – Vishal Siddhpara, shares his personal experience of how not learning JavaScript came back to bite him when he chose to learn JavaScript frameworks like Node and Express.

“It was a very challenging task for me to write code in Node and Express with every new feature and functionality implementation. I got trapped in some silly problems as well. And then, suddenly, there were some new words like closures, event loop, callbacks, and prototype roaming around me.

I felt like I was a novice to JavaScript. In fact, this was something of a mysterious monster, instead of a toddler playing in its cradle, challenging me on every other step for not considering it as a serious matter. Phewww!”

Shortcut is not the ultimate key to learning JavaScript. If you want to become a developer, understanding and learning the fundamentals of the web will not only help you build or execute your project but can add the magic of innovation to it.

Hence, it’s recommended to learn Plain JavaScript (Vanilla JavaScript) before you move into the frameworks or libraries. Trust us, learning the core of JavaScript will help you decide which framework to choose for specific requirements.

So, if you want to become a web developer, JavaScript has become a mandatory language to learn with plain old Vanilla JavaScript first.

The first step to learning JavaScript is to get hands-on. If you are familiar with a basic understanding of JavaScript and how it works, move toward a web browser now.

Steps to open the console if you are using Google Chrome:

• From the menu bar, click View
• Scroll down to Developer
• Click Javascript Console

Along with that, you will find numerous information and good resources on the web, which can help you learn JavaScript with advanced knowledge as well.

In short, ensure to spend quality learning time to know the basics of JavaScript, irrespective of your chosen methods. Once you become a master of JavaScript, you will be well-equipped to handle complex tasks and show the JavaScript benefits to the next person who is in search of finding an answer to why learn JavaScript, when alternative options - Python, Ruby, Kotlin, PHP, TypeScript, CoffeeScript, Elm, ClojureScript or Dart, are there in the market.