Head First Java 2nd Edition - Page 112, chapter 5 - Gamehelper/simpledotcom/simpledotcomgame

[john pep]

I've typed up the code exactly as is written in the book, however, i keep getting errors when trying to compile.

Below is the copy of what i've typed up.

public class SimpleDotComGame {

public static void main (String [] args) {

int numOfGuesses = 0; // make a variable to track guesses

GameHelper helper = new GameHelper(); // this object's class has method for inp

SimpleDotCom theDotCom = new SimpleDotCom(); // instantiate dot com object 

int randomNum = (int) (Math.random() * 5); // make a random number for first cell of location

int [] locations = (randomNum, randomNum+1, randomNum+2);
theDotCom.setLocationCells(locations); // location in array is given to dotcom
boolean isAlive = true; // boolean value tracks game state

while(isAlive == true) {

String guess = helper.getUserInput("enter a number"); // get user input string
String result = theDotCom.checkYourself(guess); // ask dotcom to check the guess
numOfGuesses++; // increment guess count

if (result.equals("kill")) { // i fit was a kill, turn isalive to false
   isAlive = false;
   System.out.println("You took " + numOfGuesses + " guesses"):
} // end if 

} // end while

} //end main

} // end class

import java.io.*;
class Gamehelper {
public String getUserInput(String prompt) {
String inputLine = null;
System.out.print(prompt + " ");
try {
BufferedReader is = new BufferedReader {
new InputStreamReader(System.in));
inputLine = is.readLine();
if (inputLine.length() == 0 } return null;
} catch (IOException e ) {
System.out.println("IOException: " + a);
}
return inputLine;
}


 class SimpleDotCom {

   int [] locationCells;
   int numOfHits = 0;

   public void setLocationCells(int [] locs) {
      locationCells = locs;
    }

    
   public String checkYourself(String stringGuess) {
      int guess = Integer.parseInt(stringGuess);
      String result = "miss";
      for (int cell: locationCells) {
         if (guess == cell) {
         result = "hit";
         numOfHits++;
         break;
} // close for loop 
} // get out of the loop


   if (numOfHits == locationCells.length) {
       result = "kill";
    }

   System.out.println(result);
   return result;
} // close method
} // close class

Could anyone with a sharp eye, knowledge and with a copy of the book point to where exactly I'm going wrong?

Thank you so much!

[john pep]

I've changed the Helper object instantiation, was previously upper case.
Still doesn't compile.

[Jeanne Boyarsky]

I've added code tags to make the post more readable.

At a glance, you are missing imports. You need "import java.io.*;" at a minimum up top. (I do see it further down, but it needs to be on top if this is all in one file.) After adding that, can you post what compiler errors you get?

[john pep]

The SimpleDotComGame reaches the end of file while parsing, I'm trying to see if it's been closed properly.

I've added the import at the top thank you, the errors have been reduced by 1, 12 more to go!

Edit: the if statement in the first class used a colon, instead of the semi colon. this has now been changed. Errors are down to 11 now.

[Johan Fourie]

Hi. You have confused ( with { and { with ( a few times.

[Winston Gutkowski]

john pep wrote:The SimpleDotComGame reaches the end of file while parsing, I'm trying to see if it's been closed properly.

I don't understand that at all. You mean, you're getting this as a compiler message for SimpleDotComGame.java?

Errors are down to 11 now...

And as Jeanne said: we can't do much unless we see them (the exact messages, please). Unless you're happy to just keep posting your error count.

Winston

[Binh Phan]

Hi guys,

I know this is quite an old thread but I am also stuck with the same problem. My simpleDotComGame doesn't want to compile for any reason

package com.company;

public class SimpleDotComGame {
    public static void main(String[] args) {
        int numOfGuesses = 0;
        GameHelper helper = new GameHelper();

        SimpleDotCom theDotCom = new SimpleDotCom();
        int randomNum = (int) (Math.random() *5);

        int[] locations = (randomNum, randomNum+1, randomNum+2);
        theDotCom.setLocationCells(locations);
        boolean isAlive = true;

        while(isAlive == true) {
            String guess = helper.getUserInput("enter a number");
            String result = theDotCom.checkYourself(guess);
            numOfGuesses++;
            if(result.equals("kill")) {
                isAlive = false;
                System.out.println("You took " + numOfGuesses + " guesses");
            }
        }
    }
}

Hope you guys can help. I have the other classes in the same directory but in different class files. Also my IntelliJ Idea tells me that randomNum is never used, but I just declared it there. I don't get it.

[Campbell Ritchie]

Welcome to the Ranch

Please post the error message; we can only help if we know the details of the problem.
Something else: never write == true or == false. Both are poor style and error‑prone; you might write = by mistake.
Never
while (isAlive == true) ...
Always
while (isAlive) ...
Never
while (isAlive == false) ...
Always
while (!isAlive) ...

[Binh Phan]

Thanks for the warm welcome 😁

I wanted to post the error message but I couldn‘t find the edit button 😅
I already figured out the mistake I did. Te problem was that instead of {} in the int[], I used ().
But thanks for your tip though. I will try to keep that in mind 😃

[Campbell Ritchie]

Binh Phan wrote:Thanks for the warm welcome 😁

That's a pleasure

. . . I couldn‘t find the edit button 😅

We have hidden it. You can post the error message as a new post.

. . . instead of {} in the int[], I used (). . . .

I missed that. Sorry. I shall have to put my reading glasses on