Faster, better AI-powered code reviews. Start your free trial!  
Faster, better AI-powered code reviews.
Start your free trial!

Get high quality AI code reviews

Yup Javascript: Javascript Explained

Table of Contents

Javascript is a high-level, interpreted programming language that is widely used to create interactive web applications. With its extensive capabilities and browsers’ interpreter abilities, Javascript has become the de facto language for web development and continues to shape the internet as we know it today. In this article, we will explore the fundamentals of programming in Javascript, and the best practices for using the language to write clean, efficient code.

Introduction to Javascript

Javascript was created in 1995 by Netscape engineer Brendan Eich. It was designed to be a dynamic scripting language that could be used to make web pages interactive and provide better user experiences. Since then, it has grown to become one of the most popular programming languages in the world, powering many of the websites we use on a day to day basis.

The language is based on the ECMAScript standard, which is a scripting language specification developed by the ECMA International standards organization. This standard defines what a valid Javascript program must look like and the behavior expected from it when executed. All current browsers support ECMAScript, though they may not adhere to the same level of compliance or have some additional features enabled.

Javascript is a versatile language that can be used for a variety of tasks, from creating interactive web pages to developing complex web applications. It is also used in server-side programming, mobile development, and game development. With its wide range of uses, Javascript is an essential tool for any web developer.

What is Javascript and How Does it Work?

Javascript is a high-level interpreted programming language. It is used to create dynamic webpages, applications, and other interactive content on the web. It is typically run in the browser, where it reads and executes code as users interact with the page. Additionally, since Javascript is a dynamic language, it can be used to process user data and make decisions based on that data.

A Javascript program consists of a collection of statements, variables and functions that are divided into logical sections or blocks. These blocks are executed one after the other by the JavaScript interpreter in order to execute the commands asked for. The output from a program is usually HTML, which is then sent to the browser and rendered as a webpage.

Javascript is a powerful language that can be used to create complex web applications. It is also used to create interactive elements on webpages, such as animations, games, and other interactive content. Additionally, Javascript can be used to create mobile applications, desktop applications, and even server-side applications.

Basic Syntax and Data Types

The syntax for writing in Javascript is similar to other programming languages. It supports basic principles like variables, data types, functions, operators and control flow statements like loops. Variables are used to store data and the data types supported are string, number, boolean, null and undefined.

Javascript also supports block-level scoping, allowing you to declare variables that are visible only within a specific block of code. This allows you to avoid unintentional variable collisions when writing complex programs with multiple code blocks.

In addition, Javascript also supports object-oriented programming, which allows you to create objects with properties and methods that can be used to store and manipulate data. This makes it easier to write complex programs that can interact with each other in meaningful ways.

Variables and Constants

Variables are used to store data in Javascript programs. These variables have an associated data type that dictates how the data is stored in memory. Data stored in variables can be accessed and modified during execution. Variables can also be declared with the keyword ‘var’ or ‘let’. The former is preferred as variables declared using ‘var’ are hoisted in memory, meaning that they are available throughout the program regardless of where they were declared.

Constants are special variables that cannot be modified once they are defined. This can be useful for storing values that you want to remain unchanged throughout execution of the program. Constants are declared using the ‘const’ keyword.

Operators and Expressions

Javascript supports a wide range of operators, including arithmetic (addition, multiplication, etc.), assignment (assigning values to variables), comparison (determining if two values are equal or not), logical (combining conditions with logical operators) and others. Expressions are combinations of values that are evaluated with one or more operators. These expressions produce a result that can be stored in a variable or used as an input for a function.

Control Flow and Loops

Javascript supports various types of control flow statements for writing code that conditinally executes certain blocks of code based on certain conditions. This includes if/else statements for evaluating conditions and running different blocks of code depending on the outcome, switch statements for evaluating values against a set of possible options, and loops for iterating over collections of items.

Loops in Javascript Include for loops for looping over a set of statements based on a condition, while loops for running until a condition is met, do…while loops for running once before evaluating a condition, and for…in and for…of loops for looping over iterable objects like arrays and strings.

Functions and Object-Oriented Programming

Javascript supports the concept of functions, which act as reusable blocks of code that can be used multiple times throughout the life cycle of a program. Functions can also accept inputs and return values depending on their purpose. In addition to standard functions, Javascript also supports object-oriented programming techniques.

In object-oriented programming, chunks of data are modeled into objects. These objects can then interact with each other by sending messages or changing their internal state based on one another’s input. It is an effective way of breaking complex problems into smaller chunks of logic and grouping related data together.

Error Handling in Javascript

Javascript provides error handling features for writing safe code. The most common type of error handling is the ‘try…catch’ statement which allows you to attempt an operation and catch any errors that may occur during its execution. You can also throw custom errors within try…catch blocks to refer back to specific problems within your codebase.

Popular Libraries and Frameworks for Javascript Development

To further improve developer experience when writing programs in Javascript, open source libraries like jQuery and React have been introduced to make coding easier. These libraries offer features such as user-friendly interfaces and powerful features such as AJAX capability that can save development time and effort. Additional frameworks such as Node.js have been developed to enable server-side Javascript programs.

Benefits of Using Javascript

Developers appreciate the simplicity of using Javascript when creating web applications. With its easy learning curve and extensive capabilities, Javascript has become one of the most popular languages around the world. It is also supported by all major browsers giving developers access to powerful features including geolocation, AJAX requests, HTML5 topics such as WebGL.

Tips for Writing Cleaner Code with Javascript

Writing efficient code in Javascript requires knowledge of best coding practices. This includes avoiding global variables, declaring functions with necessary arguments, avoiding excessive nesting of structures, properly formatting your code with white space, and following coding guidelines recommended by reliable sources.


Javascript is an extremely powerful programming language used extensively by web developers around the world. Beyond basic syntax, it supports advanced features like object-oriented programming that allow developers to create complex web applications quickly and easily. We hope this article has provided an overview of what Javascript is and how it works so that you can begin using it effectively in your web development projects.

Nisha Kumari

Nisha Kumari

Nisha Kumari, a Founding Engineer at Bito, brings a comprehensive background in software engineering, specializing in Java/J2EE, PHP, HTML, CSS, JavaScript, and web development. Her career highlights include significant roles at Accenture, where she led end-to-end project deliveries and application maintenance, and at PubMatic, where she honed her skills in online advertising and optimization. Nisha's expertise spans across SAP HANA development, project management, and technical specification, making her a versatile and skilled contributor to the tech industry.

Written by developers for developers

This article was handcrafted with by the Bito team.

Latest posts

Mastering Python’s writelines() Function for Efficient File Writing | A Comprehensive Guide

Understanding the Difference Between == and === in JavaScript – A Comprehensive Guide

Compare Two Strings in JavaScript: A Detailed Guide for Efficient String Comparison

Exploring the Distinctions: == vs equals() in Java Programming

Understanding Matplotlib Inline in Python: A Comprehensive Guide for Visualizations

Top posts

Mastering Python’s writelines() Function for Efficient File Writing | A Comprehensive Guide

Understanding the Difference Between == and === in JavaScript – A Comprehensive Guide

Compare Two Strings in JavaScript: A Detailed Guide for Efficient String Comparison

Exploring the Distinctions: == vs equals() in Java Programming

Understanding Matplotlib Inline in Python: A Comprehensive Guide for Visualizations

Get Bito for IDE of your choice