Problem with keeping score with a while loop (Java)

Question

I am in an intro to the java class, and for one of my assignments, I have to use a loop (for or while) to keep track of scores between myself and the computer.

Here is the exact word for word instructions from my professor:

Write a program that does this: You (as a programmer) are the dealer. pick a random number for yourself (between 0 - 100). Ask the user to input a random number (between 0 - 100) Whoever is closer to 21 wins the game.

(part 2) -Loop (keeping a counter) rite the same program and keep it going so that it keeps playing (dealing hands and saying who wins) until the user enters 21 at which point you print out some stats and say goodbye. For example, your goodbye might look like this:

Number of rounds played: 5 Dealer won: 3 Player won:2

you're 2 for 5.

Now I have written the code and played around it for hours and hours, and cannot make it work with a loop. I've tried while, do while, and for. I have looked everywhere on the internet for similar examples but cannot make a loop work in my program whatsoever. If anyone has any suggestions I would sure appreciate the feedback.

my code:

    import java.util.*;

class asd {


    public static void main(String[] args) {


        Scanner sc = new Scanner(System.in);
        System.out.println("Welcome Valued player, take your guess!");


        int min = 0;
        int max = 100;
        int input;
        int c = 21;
        int count = 0;
        int userscore = 0;
        int dealerscore = 0;
        int gamesplayed = 0;


        Random rand = new Random();


        int r = rand.nextInt(max - min) + min;
        input = sc.nextInt();
        System.out.println("computer's number:" + r);


        if (Math.abs(input - c) <= Math.abs(r - c)) {
            System.out.println("the winner is the user!" + input);
            dealerscore++;
            gamesplayed++;


        } else {
            System.out.println("the winner is the computer!" + r);
            userscore++;
            gamesplayed++;
        }
        if (input == c) {
            System.out.println("thank you for playing. you won.");

        }

        if (r == c) {
            System.out.println("Thank you for playing:" + userscore);
            System.out.println(userscore);


        }

        if (input == 0) {
            System.out.println("Number of hands played:" + gamesplayed);
            System.out.println("Dealer won:" + dealerscore);
            System.out.println("User won:" + userscore);
        }

        while (input != c && r != c)
            gamesplayed++;


    }


    // TODO code application logic here
}

Everything works fine, but I can't get the loop to work anywhere here.

Answer 1

You need a while loop that contains your game logic. The condition should just check if the input != c.

Then inside the loop, keep asking the user for input. Also, you mixed up userscore and dealerscore when adding the score.

Then at the end, once you come out of the loop, you can print the scores/stats.

Please read the comments below:

import java.util.*;

public class MyClass {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        System.out.println("Welcome Valued player, take your guess!: ");

        int min = 0;
        int max = 100;
        int input;
        int c = 21;
        int count = 0;
        int userscore = 0;
        int dealerscore = 0;
        int gamesplayed = 0;

        Random rand = new Random();
        int r = rand.nextInt(max - min) + min;
        input = sc.nextInt();

        /*
        This loop runs the game until the user enters 21
        */
        while (input != c) {
            System.out.println("Computer's number:" + r);

            if (Math.abs(input - c) <= Math.abs(r - c)) {
                System.out.println("The winner is the user! " + input);
                userscore++; //You mixed up userscore and dealerscore
            } else {
                System.out.println("The winner is the computer! " + r);
                dealerscore++; //You mixed up userscore and dealerscore
            }

            /*
            User needs to keep entering guesses
            */
            System.out.println();
            System.out.println("Enter another guess: ");
            r = rand.nextInt(max - min) + min;
            input = sc.nextInt();
        }

        /*
        You don't need any conditions since the games have already ended
        But it should be outside and after the loop
        */
        System.out.println("Number of hands played:" + gamesplayed);
        System.out.println("Dealer won:" + dealerscore);
        System.out.println("User won:" + userscore);
    }
}

Answer 2

Try this. Just refer to the code for explanations.

import java.util.Random;
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {

        Scanner sc = new Scanner(System.in);
        System.out.println("Welcome Valued player, take your guess!");
        System.out.println("");

        int min = 0;
        int max = 100;
        int input;
        int c = 21;
        int userscore = 0;
        int dealerscore = 0;
        int gamesplayed = 1;

        Random rand = new Random();

        while (true) { // so that the game will keep playing
            System.out.println("----------------- ROUND " + gamesplayed + " -----------------");
            int r = rand.nextInt(max - min) + min; // computer's choice

            while (true) { // so that it will keep asking the user in case the user enters an invalid input
                try {
                    System.out.print("Enter a random number! :");
                    input = Integer.parseInt(sc.nextLine());
                    break;
                } catch (Exception e) {
                    System.out.println("Invalid input!");
                }
            }

            System.out.println("The computer's random number is " + r);

            // checking for the rounds winner
            if (Math.abs(input - c) <= Math.abs(r - c)) {
                System.out.println("The winner is the user!");
                userscore++;
            } else {
                System.out.println("The winner is the computer!");
                dealerscore++;
            }

            if (input == c) { // checking for ending the game
                System.out.println("================ GAME STATS ================");
                System.out.println("Thank you for playing.");
                System.out.println("Number of hands played: " + gamesplayed);
                System.out.println("Dealer score: " + dealerscore);
                System.out.println("User score: " + userscore);
                System.out.println("You are " + userscore + " out of " + gamesplayed + "!");
                System.out.println("============================================");
                sc.close();
                break;
            }

            gamesplayed++; // increment games played

            System.out.println("--------------------------------------------");
        }

    }

}

Answer 3

Change the loop with

      while (input != c && r != c){
          gamesplayed++;
          System.out.println("Games played: " + gamesplayed );
      }

you will see it is working. I would format the code better to debug it easier and always use the brackets.