Head First Java SimpleDotCom program help please...

[James Conroy]

Hi,
I am having a problem with the SimpleDotCom program in the Head First Java book (chapter 5). I have completed chapter 5 and my program (basic version) works correctly except for one bug. Here's my source code:

public 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;
		}
	}
	
	if (numOfHits ==
		locationCells.length) {
		result = "kill";
	}
	System.out.println(result);
		return result;
	}		
}		

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");
	}
	}
}

import java.io.*;
public 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: " + e);
     }
     return inputLine;
  }
}

When I run the program, it tells me how many guesses I've taken after every data input instead of at the end when isAlive is false and the ship is killed. Let me show you an example:

c:\Java>java SimpleDotComGame
enter a number  1
miss
You took 1 guesses
enter a number  2
miss
You took 2 guesses
enter a number  3
miss
You took 3 guesses
enter a number  4
hit
You took 4 guesses
enter a number  5
hit
You took 5 guesses
enter a number  6
kill
You took 6 guesses

What am I doing wrong?

Many thanks in advance,
James.

[Mohamed Sanaulla]

Hi James, Welcome to JavaRanch,
There's subtle error in the code. If you dont specify the {} with the if-else statement then the compiler considers the immediate next statement as part of the if statement and statements following the immediate statement are not considered as part of the if-statement. If you have multiple statements in the if-else block, put them in the {}. But generally its more readable to separate such if-else constructs using the {}

[Mohamed Sanaulla]

I would suggest you to read this section from the Java tutorials which cautions the programmers to such kind of errors.