Thread: Need to write a public instance method for a simple dice program

Hi,

Not sure where to start here or what detail you will need, as you can guess, I'm pretty darn new to all this! Ok, here goes. I am working through an assignment, in this particular section I need to write

"...a public instance method which takes a single int argument and returns no value. The method should first check that its argument is in the range 1 to 6 (inclusive). If it isn't the method should display in a dialogue box a message, if the value of the argument is in the correct range the mehod should send one of the 'face' messages to the recevier, this. For example if the value of the argument is 1, the method should send the message face1() to the receiver etc.."

So what I guess I need to do here is something along the lines of:

if face is >= 6 or <=0
display the message
else
send the message facex() to the receiver

I've tried different ways to acheive this, but I'm getting no where fast.

The latest way I have written this is:

 public int changeFace()
   {
        int n;
        if ((n >= 6) || (n <= 0))
         {
            OUDialog.alert("Argument to changeFace() message " +  (n) +" is out of range");
         }
        else
         {
            return this.changeFace(n);
         }
    }

but when I try to compile in BlueJ I get an error: "changeFace() in Dice cannot be applied to (int)"

I'm not sure how much detail is required, so I've tried to include what I think is relevant, but if there is anything else that is of use, please let me know

Thanks!

The method criteria is: "a public instance method which takes a single int argument and returns no value". Your method signature does not match the criteria. (Signature refers to the return type and number+type of arguments) As to what face1() refers to, it's hard to say, but the format would suggest a method. Some more information may help to clear that up.

Hi,

This is a copy of the code for face1()

/**
    * Sets the face of the receiver to 1 spot
    */
   public void face1()
   {
      this.getTopLeftSpot().setColour(OUColour.ORANGE);
      this.getTopMiddleSpot().setColour(OUColour.ORANGE);
      this.getTopRightSpot().setColour(OUColour.ORANGE);
      this.getMiddleSpot().setColour(OUColour.BLUE);
      this.getBottomLeftSpot().setColour(OUColour.ORANGE);
      this.getBottomMiddleSpot().setColour(OUColour.ORANGE);
      this.getBottomRightSpot().setColour(OUColour.ORANGE);
   }

There is one these for each face of the dice, 1 - 6

Originally Posted by akira25

"...a public instance method which takes a single int argument and returns no value. The method should first check that its argument is in the range 1 to 6 (inclusive). If it isn't the method should display in a dialogue box a message, if the value of the argument is in the correct range the mehod should send one of the 'face' messages to the recevier, this. For example if the value of the argument is 1, the method should send the message face1() to the receiver etc.."

 public int changeFace()
   {
        int n;
        if ((n >= 6) || (n <= 0))
         {
            OUDialog.alert("Argument to changeFace() message " +  (n) +" is out of range");
         }
        else
         {
            return this.changeFace(n);
         }
    }

Hello akira25!
I think you should first make your changeFace() method match the criteria you are given (which does not as post #2 said). With the int signature your method should return an int value but your criteria want it to return no value. And also right now it takes no argument instead of an int argument that is supposed to.
I would suggest you to read the javadoc for methods and a useful tutorials.