What Is Java and Setting Up the JDK

// File: HelloWorld.java
// Compile: javac HelloWorld.java
// Run:     java HelloWorld

public class HelloWorld {

    /**
     * The main method is the entry point for every Java application.
     * The JVM looks for this exact signature when starting execution.
     *
     * @param args command-line arguments passed to the program
     */
    public static void main(String[] args) {
        // Print a greeting to standard output
        System.out.println("Hello, World!");

        // Print the current Java version at runtime
        String version = System.getProperty("java.version");
        System.out.println("Running on Java " + version);

        // Demonstrate System.out.printf for formatted output
        String name = "Java Developer";
        System.out.printf("Welcome, %s!%n", name);

        // Show that args can be iterated
        if (args.length > 0) {
            System.out.println("Command-line arguments received:");
            for (String arg : args) {
                System.out.println("  " + arg);
            }
        } else {
            System.out.println("No command-line arguments were provided.");
        }
    }
}