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Thread: Code guessing game, need help with arrays

  1. #1
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    Default Code guessing game, need help with arrays

    Hey everyone,

    So I made the following code... It does what it's expected to do, however it's not efficiŽnt at all.
    It's a game where you have to guess at least 3 'secret numbers' to win. The secret code consists of 5 numbers that are either 1 or 2.

    public class CodeGuessingGame {
     
     
        public static void main(String[] args) {
     
            Scanner scan = new Scanner(System.in);
            int[] guess = {0, 1, 2, 3, 4};
     
            System.out.println("Let the game begin...");
            System.out.println("Guess my secret code, consisting of 1 and 2");
            System.out.println(" ");
     
     
                System.out.print("Guess number 1 (1 or 2): ");
                guess[0] = scan.nextInt();
     
                System.out.print("Guess number 2 (1 or 2): ");
                guess[1] = scan.nextInt();
     
                System.out.print("Guess number 3 (1 or 2): ");
                guess[2] = scan.nextInt();
     
                System.out.print("Guess number 4 (1 or 2): ");
                guess[3] = scan.nextInt();
     
                System.out.print("Guess number 5 (1 or 2): ");
                guess[4] = scan.nextInt();
     
                System.out.println(" ");
                System.out.println("Your guess: " + "[" + guess[0] + "]" + "[" + guess[1] + "]" + "[" + guess[2] + "]" + "[" + guess[3] + "]" + "[" + guess[4] + "]");
     
                int secretNumber1;
                secretNumber1 = (int) (Math.random() * 2 + 1);
     
                int secretNumber2;
                secretNumber2 = (int) (Math.random() * 2 + 1);
     
                int secretNumber3;
                secretNumber3 = (int) (Math.random() * 2 + 1);
     
                int secretNumber4;
                secretNumber4 = (int) (Math.random() * 2 + 1);
     
                int secretNumber5;
                secretNumber5 = (int) (Math.random() * 2 + 1);
     
                System.out.println("Secret code: " + "[" + secretNumber1 + "]" + "[" + secretNumber2 + "]" 
                        + "[" + secretNumber3 + "]" + "[" + secretNumber4 + "]" + "[" + secretNumber5 + "]");
     
                if (((guess[0] == secretNumber1) && (guess[1] == secretNumber2) && (guess[2] == secretNumber3)) || 
                        (guess[1] == secretNumber2) && (guess[2] == secretNumber3) && (guess[3] == secretNumber4) || 
                        (guess[2] == secretNumber3) && (guess[3] == secretNumber4) && (guess[4] == secretNumber5) || 
                        (guess[0] == secretNumber1) && (guess[1] == secretNumber2) && (guess[4] == secretNumber5) ||
                        (guess[0] == secretNumber1) && (guess[3] == secretNumber4) && (guess[4] == secretNumber5) ||
                        (guess[0] == secretNumber1) && (guess[2] == secretNumber3) && (guess[4] == secretNumber5) ||
                        (guess[1] == secretNumber2) && (guess[3] == secretNumber4) && (guess[4] == secretNumber5) ||
                        (guess[0] == secretNumber1) && (guess[1] == secretNumber2) && (guess[3] == secretNumber4) ||
                        (guess[1] == secretNumber2) && (guess[2] == secretNumber3) && (guess[4] == secretNumber5) ||
                        (guess[0] == secretNumber1) && (guess[2] == secretNumber3) && (guess[3] == secretNumber4))
                    System.out.println("You guessed 3 or more correct, therefore you win");
                else
                    System.out.println("You did not guess 3 or more correct, therefore you lose");
     
     
        }
    }

    One of the possible outcomes is the following:
    Let the game begin...
    Guess my secret code, consisting of 1 and 2

    Guess number 1 (1 or 2): 1
    Guess number 2 (1 or 2): 2
    Guess number 3 (1 or 2): 2
    Guess number 4 (1 or 2): 1
    Guess number 5 (1 or 2): 1

    Your guess: [1][2][2][1][1]
    Secret code: [1][1][1][1][2]
    You did not guess 3 or more correct, therefore you lose

    There should be a way to count how many of the guessed numbers are the same as the numbers of the secret code without having to write every solution there is. How do I do this?
    Also, are there any other ways to shorten my code? I have tried a couple of things to do this but no luck so far since I'm pretty new in Java programming. I'm assuming I can do this with arrays, but I still find this pretty confusing.


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    Default Re: Code guessing game, need help with arrays

    Anytime you start naming variables this1, this2, this3, . . . thisX, think "The variable 'this' should be an array." With the secret code and user's guessed digits both in an array, a loop can be used to get the user's guesses and compare each one to the secret code each pass through the loop. Results can be collected in another array, perhaps a boolean, and then presented at the end.

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    Warow (November 16th, 2013)

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    Default Re: Code guessing game, need help with arrays

    Thanks for the quick reply. Although it sounds pretty logical, I can't quite imagine how I'd do this. Might you have an example I can see?

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    Default Re: Code guessing game, need help with arrays

    For example, this:
       System.out.print("Guess number 1 (1 or 2): ");
       guess[0] = scan.nextInt();
     
       System.out.print("Guess number 2 (1 or 2): ");
       guess[1] = scan.nextInt();
     
       System.out.print("Guess number 3 (1 or 2): ");
       guess[2] = scan.nextInt();
     
       System.out.print("Guess number 4 (1 or 2): ");
       guess[3] = scan.nextInt();
     
       System.out.print("Guess number 5 (1 or 2): ");
       guess[4] = scan.nextInt();
    could be reduced to this (untested):
           for ( int i = 0 ; i < guess.length ; i++ )
           {
               System.out.print("Guess number " + ( i + 1 ) + " (1 or 2): ");
               guess[i] = scan.nextInt();
           }
    Once you see how to do it with the guess[] array, you should be able to add similar treatment to the secret number.

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    Warow (November 16th, 2013)

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    Default Re: Code guessing game, need help with arrays

    Thanks once more for your reaction. I've changed the first bit to:
               for (int i=0; i<5; i++) {
                   secretNumber[i] = (int) (Math.random() * 2 + 1);
               }
               System.out.print("Secret code: " + "[" + secretNumber[0] + "]" + "[" + secretNumber[1] + "]" + "[" + secretNumber[2] 
                                                                + "]" + "[" + secretNumber[3] + "]" + "[" + secretNumber[4] + "]");

    The part with the secret numbers still confuses me though. I changed that to:
    for (int i=0; i<5; i++) {
                   secretNumber[i] = (int) (Math.random() * 2 + 1);
               }
               System.out.print("Secret code: " + "[" + secretNumber[0] + "]" + "[" + secretNumber[1] + "]" + "[" + secretNumber[2] + "]" + "[" + secretNumber[3] + "]" + "[" + secretNumber[4] + "]");
    However, now I am lost in how I count the amount of rightly guessed numbers.

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    Default Re: Code guessing game, need help with arrays

    Write out with pencil on paper what you need to accomplish and in the order it should be accomplished. The result should be something like:

    set the secret numbers,
    get the user's guesses, comparing each guess to the corresponding secret number
    print the results

    The 3 lines above could be expanded to included the more minor, supporting details.

    So in your second loop above, a good start, you wouldn't want to print the secret numbers as they're being set.

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    Warow (November 16th, 2013)

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    Default Re: Code guessing game, need help with arrays

    Finally works. Added:
    int count = 0;
               for (int i=0; i<5; i++) {
               if (secretNumber[i] == guess[i])
                    count++;
                  }
     
                if (count >= 3)
                System.out.println("You guessed " + count + " numbers correct, therefore you win");
                else
                System.out.println("You only guessed " + count + " number(s) correct, therefore you lose");

    Thanks a lot for your help Greg!

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    Default Re: Code guessing game, need help with arrays

    Very good. Glad to help.

    Try to avoid the use of "magic numbers," like the i < 5 in your for loop. Throughout your program, you could have used a constant, like NUMBER_OF_DIGITS (or some name you like better) to indicate how many digits there'd be in the secret number. This constant would then drive the size of the arrays guess[] and secretNumber[] and could be used as a loop limit. When the size of an array is the loop limit, you can and should use:

    for ( int i = 0 ; i < myArray.length ; i++ )

    The advantage of using a constant like NUMBER_OF_DIGITS is that you only have to change the value in one place - where NUMBER_OF_DIGITS is initialized - to update the whole program to handle a different sized secret number. When 'magic numbers' are used, a simple change like adding another digit to the secret number becomes very painful.

    Keep coding!

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