JavaScript 2025: where to start learning in practice

Introduction to JavaScript: where to start in 2025 in practice

JavaScript remains one of the most in-demand programming languages in the world. In 2025, it not only maintains its position but is also actively expanding: from frontend to server-side development on Node.js, mobile applications, and even embedded systems. If you have decided to start learning JavaScript right now, this guide will help you take your first steps from a practical perspective. We will cover how to set up your environment, write your first programs, and explore key concepts that every developer will find useful.

Why JavaScript in 2025?

JavaScript is the language that powers virtually every modern website. But in 2025, its significance has extended far beyond the browser. Thanks to the Node.js platform, you can write server applications, APIs, chatbots, and even desktop programs. The main reasons to choose JavaScript today are:

• Versatility: one language for frontend and backend.
• Huge community: millions of developers, thousands of libraries and frameworks.
• High demand: there are more job openings for JS developers than for many other languages.
• Quick start: no complex tools needed — just a text editor and Node.js.

To make learning as effective as possible, we will work not in the browser, but in the Node.js environment. This will give you full control over the process and prepare you for real-world development.

Step 1. Installing and setting up the environment

The first thing you need to do is install Node.js. This is a JavaScript runtime environment outside the browser. Go to the official website nodejs.org and download the LTS version (recommended for most users). The installation is standard — just follow the installer instructions.

After installation, open a terminal (command line) and check that everything is working:

node --version

You will see a version number, for example, v22.0.0. Also check the npm package manager:

npm --version

Now create a folder for your project, for example js-intro, and navigate into it:

mkdir js-introcd js-intro

Create a file index.js — we will write code in it. Open this file in any text editor (VS Code, Sublime Text, Notepad++).

Step 2. First program on Node.js

Let's write the classic "Hello, World!". Open index.js and add:

// First program in JavaScriptconsole.log("Hello, world! JavaScript 2025");

Save the file and run it in the terminal:

node index.js

You will see in the console: Hello, world! JavaScript 2025. Congratulations, you have just run your first program on server-side JavaScript!

The console.log() function is the equivalent of print() in Python. It outputs data to the terminal. This is the primary tool for debugging and checking code execution.

Step 3. Syntax basics: variables, data types, functions

Now let's look at the basic constructs that every program uses.

Variables

In JavaScript, there are three ways to declare a variable: var, let, and const. In 2025, it is recommended to use let and const:

// Mutable variablelet name = "Alexey";name = "Maria"; // can be changed

// Immutable constantconst birthYear = 1995;// birthYear = 2000; // Error! Cannot reassign const

console.log(name, birthYear);

Data types

JavaScript is a dynamically typed language. The main types are:

• S