Introduction to Java Programming

Java is one of the most popular programming languages in the world. It is widely used for building desktop applications, web applications, mobile apps (Android), and even enterprise systems.

If you are starting your programming journey, learning Java is a great choice because:

• It is object-oriented, making it easier to understand real-world problems.
• It runs on the Java Virtual Machine (JVM), which makes it platform-independent.
• It has a huge community, tutorials, and job opportunities.

Key Features of Java

1. Simple and easy to learn—especially for beginners.
2. Object-Oriented—everything in Java is based on classes and objects.
3. Platform Independent—”Write “once, run anywhere.”
4. Secure and Robust – prevents errors and provides memory management.
5. High Performance—optimized for speed with just-in-time compilation.

Java Install

However, if you want to run Java on your own computer, follow the instructions below.

Some PCs might have Java already installed.

To check if you have Java installed on a Windows PC, search in the start bar for Java or type the following in Command Prompt (cmd.exe):

C:\Users\Your Name>java -version

If Java is installed, you will see something like this (depending on version):

java version “22.0.0” 2024-08-21 LTS
Java(TM) SE Runtime Environment 22.9 (build 22.0.0+13-LTS)
Java HotSpot(TM) 64-Bit Server VM 22.9 (build 22.0.0+13-LTS, mixed mode)

If you do not have Java installed on your computer, you can download it at oracle.com.

Note: In this tutorial, we will write Java code in a text editor. However, it is possible to write Java in an Integrated Development Environment, such as IntelliJ IDEA, Netbeans or Eclipse, which are particularly useful when managing larger collections of Java files.

First Java Program Example

In Java, every application begins with a class name, and that class must match the filename.

Let’s create our first Java file, called Main.java, which can be done in any text editor (like Notepad).

The file should contain a “Hello World” message, which is written with the following code:

public class Main {
  public static void main(String[] args) {
    System.out.println("Hello World");
  }
}

Explanation of Code

• class Main → Defines a class named Main.
• public static void main(String[] args) → The entry point of every Java program.
• System.out.println("Hello, World!"); → Prints text to the console.

Don’t worry if you don’t understand the code above – we will discuss it in detail in later chapters. For now, focus on how to run the code above.

Save the code in Notepad as “Main.java”. Open Command Prompt (cmd.exe), navigate to the directory where you saved your file, and type “javac Main.java”:

C:\Users\Your Name>javac Main.java

This will compile your code. If there are no errors in the code, the command prompt will take you to the next line. Now, type “java Main” to run the file:

C:\Users\Your Name>java Main

The output should read:

Hello World

Applications of Java

Java is used in many areas, such as:

• Mobile Apps → Android apps are mostly built with Java.
• Web Development → Using frameworks like Spring.
• Enterprise Applications → Banking systems, ERP software.
• Games → Some popular games use Java as a base language.

Why Should You Learn Java?

• Strong foundation for understanding other programming languages.
• Huge demand in the job market.
• Prepares you for advanced topics like Data Structures, Algorithms, and Object-Oriented Design.

Conclusion

Java is a beginner-friendly yet powerful programming language. By learning Java, you can build everything from small console programs to complex enterprise systems.

👉 In the next post, we’ll cover Java Variables and Data Types with examples.