জাভা ফাংশন

public class Main {
  static void message() {
    System.out.println("হ্যালো বিশ্ব");
  }

  public static void main(String[] args) {
    message();
  }
}

public class Main {
  static void message() {
    System.out.println("হ্যালো বিশ্ব");
  }

  public static void main(String[] args) {
    message();
  }
}

public class Main {
  static String message() {
    return "হ্যালো বিশ্ব";
  }

  public static void main(String[] args) {
    System.out.println(message());
  }
}

public class Main {
  static String message() {
    return "হ্যালো বিশ্ব";
  }

  public static void main(String[] args) {
    System.out.println(message());
  }
}

public class Main {
  interface Message {
    String call(String text);
  }

  public static void main(String[] args) {

    Message message = text -> text;

    System.out.println(
      message.call("হ্যালো বিশ্ব")
    );
  }
}

public class Main {
  static String user(String name, String land) {
    return name + " - " + land;
  }

  public static void main(String[] args) {

    System.out.println(user("আরিফ", "বাংলাদেশ"));
  }
}

public class Main {
  static void user(String name, String land) {
    System.out.println(name + " - " + land);
  }

  public static void main(String[] args) {

    user("আরিফ", "বাংলাদেশ");
  }
}

public class Main {
  static void reference(int number) {
    number = 123456;
  }

  public static void main(String[] args) {

    int number = 100;

    reference(number);

    System.out.println(number);
  }
}

public class Main {
  static int sum(int... numbers) {

    int result = 0;

    for(int number : numbers) {
      result += number;
    }

    return result;
  }

  public static void main(String[] args) {

    System.out.println(sum(10, 15, 10, 25));
  }
}

public class Main {
  static int sum(int... numbers) {

    int result = 0;

    for(int number : numbers) {
      result += number;
    }

    return result;
  }

  public static void main(String[] args) {

    int[] numbers = {10, 15, 10, 25};

    System.out.println(sum(numbers));
  }
}

public class Main {
  static void counter(int number) {

    if(number <= 0) {
      return;
    }

    System.out.println("নাম্বার " + number);

    counter(number - 1);
  }

  public static void main(String[] args) {
    counter(10);
  }
}

public class Main {
  static String message() {
    return "হ্যালো বিশ্ব";
  }

  public static void main(String[] args) {

    java.util.function.Supplier<String>
      function = Main::message;

    System.out.println(
      function.get()
    );
  }
}

public class Main {
  static String message(String text) {
    return text;
  }

  static void call(
    java.util.function.Function<String, String>
    callback
  ) {
    System.out.println(
      callback.apply("হ্যালো বিশ্ব")
    );
  }

  public static void main(String[] args) {
    call(Main::message);
  }
}