我怎样才能在只能运行一次的循环中制作一个开关盒？

Question

Im working on an assignment and i need to make a dice game, in the game the user is supposed to be able to roll a specific dice only once per round (example dice 1 can only be rolled once) however i cannot figure out how to do that, this is what i have so far

    class Main {
public static void main(String[] args) {
  Scanner diceInput = new Scanner(System.in);
  String diceNumber = "";
  int dice1 = 0;
  int dice2 = 0;
  int dice3 = 0;
  int win = 0;
  int loss = 0;
  int sum = 0;
  int rolls = 3;
 
  //intro
  System.out.print("Welcome to the game 12. You must roll 1-3 dice and try to get the sum 12");
  // while loop that repeats until q is inputted or rolls are higher than 0
  while((!"q".equals(diceNumber)) || (rolls > 0)){
    System.out.print("\nEnter which dice you want to roll [1,2,3] (exit with q): ");
   diceNumber = diceInput.nextLine();
    sum = 0;
    //switch for specific inputs that will repeat until a valid imput is entered.
  switch(diceNumber){
    case "1":
      dice1 = (int)(Math.random()*6)+1;
      sum = dice1 + dice2 + dice3;
      rolls--;//decreases a roll when case is run
      break;
    case "2":
      dice2 = (int)(Math.random()*6)+1;
      sum = dice1 + dice2 + dice3;
      rolls--;
      break;
    case "3":
      dice3 = (int)(Math.random()*6)+1;
      sum = dice1 + dice2 + dice3;
      rolls--;
      break;
    case "q":
      System.out.println("Game Over!");
      System.exit(0);
  }
     if(sum > 12) {//adds a point to loss if score is over 12
     loss++;
   } else if(sum == 12){// point to win if score is 12
     win++;
   }
    System.out.println(dice1+" "+dice2+" "+dice3+" "+"sum "+sum+" #win "+win+" # loss "+loss);
    // displays next round message when sum = 12 or rolls = 0 and resets the value of dice
    if((rolls == 0) || (sum == 12)){
      dice1 = 0;
      dice2 = 0;
      dice3 = 0;
      System.out.println("Next Round");
      rolls = 3;

i would appreciate if the solution will be on the simpler side

Answer 1

what you want is to check whether the dice have been rolled before you execute the code inside the switch case.

There are many ways check for that, for example with a dedicated boolean variable for each dice. But in your specific case, the dice variables are all 0 until they are rolled, so you can check for that instead.

sth like this

switch(diceNumber){
    case "1":
        if(dice1!=0){
            //your code
        }
    case "2":
        if(dice2!=0){
            //your code
        }
    case "3":
        if(dice3!=0){
            //your code
        }