Ok so i was wondering what im doing wrong here

Question

i have one driver class and 2 objects that im trying to read into it. the RightArrow and LeftArrow compile but the demo class gives me these errors
F:\ArrowDemo1.java:25: setTail(int) in RightArrow cannot be applied to ()
               RightArrow.setTail();
               ^
F:\ArrowDemo1.java:29: setArrowheads(int) in LeftArrow cannot be applied to ()
     LeftArrow.setArrowheads();
     ^
F:\ArrowDemo1.java:30: setTails(int) in LeftArrow cannot be applied to ()
     LeftArrow.setTails();
     ^
4 errors
what am i doing wrong here.
public class ArrowDemo1
   public static void main(String[]args)
        Scanner keyboard = new Scanner(System.in);
        System.out.println("Do you want your arrow to point right or left");
        System.out.println("Type right or left");
        String rightLeft = keyboard.nextLine();
        if  (rightLeft.equalsIgnoreCase("right"))
                  RightArrow.setArrowhead();
                  RightArrow.setTail();
        if (rightLeft.equalsIgnoreCase("left"))
             LeftArrow.setArrowheads();
             LeftArrow.setTails();
public class LeftArrow extends Figure
     Scanner keyboard = new Scanner(System.in);
     private int base;
     private int head;
     private int tail;
     public void setArrowheads(int headsUp)
          System.out.println("Please enter a head length for your arrow");
          headsUp = keyboard.nextInt();
          if (headsUp < 1)
                  System.out.println("Sorry the head length must be larger than 0");
                  System.exit(0);
          if (headsUp >= 3)
             int oddTest = (headsUp%2);
             if (oddTest == 0)
                  System.out.println("Sorry you must enter an odd number of 3 or higher");
                  System.exit(0);
       head = headsUp;
    public void setTails(int tail)
               System.out.println("Please enter a tail length for your arrow");
               tail = keyboard.nextInt();
               if (tail < 1)
                       System.out.println("Sorry the tail length must be larger than 0");
                       System.exit(0);
public class RightArrow extends Figure
    Scanner keyboard = new Scanner(System.in);
     private int base;
     private int head;
     private int tail;
     public void setArrowhead(int heads)
          System.out.println("Please enter a head length for your arrow");
          heads = keyboard.nextInt();
          if (heads < 1)
                  System.out.println("Sorry the head length must be larger than 0");
                  System.exit(0);
          if (heads >= 3)
             int oddTest = (heads%2);
             if (oddTest == 0)
                  System.out.println("Sorry you must enter an odd number of 3 or higher");
                  System.exit(0);
       head = heads;
    public void setTail(int tails)
          System.out.println("Please enter a tail length for your arrow");
          tails = keyboard.nextInt();
          if (tails < 1)
                  System.out.println("Sorry the tail length must be larger than 0");
                  System.exit(0);
        tail = tails;
}

Answer 1

duffymo wrote:
How do you ever expect to understand Java when you can't read English?
Did you read the error messages?This is one of the things that frustrates me the most. People see an error message, and they freak out. "OMFG! I don't know enough Java to understand these mysterious runes! I need to find someone to tell me what magic spell to type (since programming is, of course, all about memorizing what to type) to make it go away!"
I know some of the messages are kind of cryptic, but many of them--this one being a prime example--are very explicit if you just take a few seconds to read it. Are people so bloody afraid to even try to engage their brains? Does nobody even have the most basic concept of observing a problem, taking a moment to study what's happening, using a tiny bit of knowledge, logic, and guesswork to come up with a potential solution or two, and then trying it out? Is everybody really so fuckityfucking helpless? Is simple analysis a lost art, doomed to go the way of [Damscus steelmaking|http://en.wikipedia.org/wiki/Damascus_steel]?
</rant>
Edited by: jverd on Mar 29, 2008 12:56 PM