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Writing Your First Java Program

Create, compile, and run a simple HelloWorld program while learning the structure of a Java application.

Writing Your First Java Program

The traditional first program prints a message to the console. In Java every executable program needs a public static void main(String[] args) method.

public class HelloWorld {
    public static void main(String[] args) {
        System.out.println("Welcome to the Java Platform!");
    }
}

Explanation:

public class HelloWorld – defines a class named HelloWorld accessible from anywhere.
public static void main(String[] args) – the entry point the JVM calls when launching the program.
System.out.println(...) – writes the supplied text followed by a newline to the standard output stream.

Remember: The class name must match the filename (HelloWorld.java) and the main method must be exactly as shown for the JVM to recognise it.

HelloWorld.java

HelloWorld.javaJAVA

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