从一个开关里走出来，但没有布尔值，这有可能吗？(Going out from a switch inside a do while, but without a boolean, it's possible? Java)

 所以这个代码是关于在一个do中给出一个输入的限制。 在这种情况下，你有3个机会继续。 在那之后停止，也有o​​portunitie停止只是提示任何键加入，而且当你开始时，你是否有oportunitie（这里进入开关）退出程序。 问题或我卡住的地方在这里。 
 
 也许这可能没有布尔值，或者可能改变或添加我还不知道的东西。 对不起，我试图找到一个答案，但我看到它是关于走出一个while循环whith布尔左右。 不是这样的。 
 
    Scanner kb = new Scanner(System.in);
    // c = continue
    char c;
    // attempt to limit the input to 3 times
    int attempt = 3;
    // option = op
    int op = 0;

    do {
        do{
            System.out.println("Choose continue[0] or go out[1].");
            while  (!kb.hasNextInt()) {
                kb.nextLine();
                System.out.println("It's not a number.");                   
            }
            op = kb.nextInt();
        } while ( op <= -1 || op >= 2 );

        switch (op) {
        case 0:
            System.out.println("Continue!");
            break;
        case 1:     //here I tried; attempt = -1  
            break;  //is where I think it needs to be something
        default:
            break;
        }

        System.out.println("Do you wanna try again,"+attempt+" less?[c]+enter\n"
                + "Any other key + enter to exit.");
        c = kb.next(".").toUpperCase().charAt(0);
        attempt--;
    } while ( attempt > 0 && ( c == 'C' ) );
            //here also to put !( op == 0 )
    kb.close();

So the code is about giving a limit of inputs in a do while. In this case you have 3 oportunities to continue. After that the do while stops, also you have the oportunitie to stop just presing any key plus enter, but also when you start, do you have the oportunitie (here enters the switch) to exit the program. The problem or where I get stuck is here. 
 
That maybe it's possible without a boolean, or maybe changing or adding something that I don't yet know. Sorry I try to find an answer but all I saw it's about going out a while loop whith boolean or so. Not like this.
 
    Scanner kb = new Scanner(System.in);
    // c = continue
    char c;
    // attempt to limit the input to 3 times
    int attempt = 3;
    // option = op
    int op = 0;

    do {
        do{
            System.out.println("Choose continue[0] or go out[1].");
            while  (!kb.hasNextInt()) {
                kb.nextLine();
                System.out.println("It's not a number.");                   
            }
            op = kb.nextInt();
        } while ( op <= -1 || op >= 2 );

        switch (op) {
        case 0:
            System.out.println("Continue!");
            break;
        case 1:     //here I tried; attempt = -1  
            break;  //is where I think it needs to be something
        default:
            break;
        }

        System.out.println("Do you wanna try again,"+attempt+" less?[c]+enter\n"
                + "Any other key + enter to exit.");
        c = kb.next(".").toUpperCase().charAt(0);
        attempt--;
    } while ( attempt > 0 && ( c == 'C' ) );
            //here also to put !( op == 0 )
    kb.close();

原文：https://stackoverflow.com/questions/47147451