Java Tutorial

Java is a general-purpose programming language. It is used to build Android apps, banking systems, web servers, desktop software and large business applications.

Java code runs on the Java Virtual Machine (JVM), so the same program can run on Windows, macOS and Linux without changes. This is why people say Java is "write once, run anywhere".

Why Learn Java?

• It is one of the most used languages in the world, and jobs that need Java are easy to find
• It teaches you object-oriented programming (classes and objects), which you will use in many other languages
• It is strict about types, so many mistakes are caught before the program even runs
• It has a huge community, free tools and lots of help online

What You Will Learn

• How to install Java and run your first program
• Syntax, output, comments, variables and data types
• Operators, strings, if...else, switch and loops
• Arrays and methods
• Classes and objects, the heart of Java

A First Example

public class Main {
  public static void main(String[] args) {
    System.out.println("Assalam o Alaikum, Java!");
  }
}

Assalam o Alaikum, Java!

Every Java program has at least one class, and it starts running from the main method. You will learn what each line means in the first chapters.

Check Yourself

What to Learn After Java

Once you know the basics, try C#, which looks very similar, or C++ to see how a lower-level language works. You can also start with C to understand how computers handle memory.