Question

所以我必须询问用户他们是否超过18岁，他们必须回答是真还是假。并保持循环直到他们输入正确的输入

到目前为止，我有这个

boolean b = false;
do {
    try {
        System.out.print("Are you above 18?");
        Scanner n = new Scanner(System.in);
        boolean bn = s.nextBoolean();

        if (bn == true) {
            // do stuff
        } else if (bn == false) {
            // do stuff
        }

    } catch (InputMismatchException e) {
        System.out.println("Invalid input!");
    }
} while (!b);

然而，它不会工作，因为循环继续前进，它不会读取输入权并执行我的if语句。我该如何解决？谢谢！

Answer 1

对您的计划稍作调整。这有效

boolean b = false;
        do {
            try {
                System.out.print("Are you above 18?");
                Scanner n = new Scanner(System.in);
                boolean bn = n.nextBoolean();
                if (bn == true) {
                    System.out.println("Over 18");
                } else if (bn == false) {
                    System.out.println("under 18");
                }

            } catch (InputMismatchException e) {
                System.out.println("Invalid input!");
            }
        } while (!b);

输出

Are you above 18?true
Over 18
Are you above 18?false
under 18
Are you above 18?

Answer 2

您需要重新检查您的扫描仪声明和初始化声明...

Scanner n = new Scanner(System.in);
boolean bn = s.nextBoolean();

应该是

Scanner n = new Scanner(System.in);
boolean bn = n.nextBoolean();

Answer 3

尝试更改

boolean bn = s.nextBoolean();

到

b = s.nextBoolean();

Answer 4

使用 -

scanner.nextBoolean（）

    do{
      try{
          System.out.print("Are you above 18?");
          Scanner scanner = new Scanner(System.in);
          if(scanner.nextBoolean()==true)
           //do stuff

          }else{

          //do stuff
          }
       }

如何使用扫描仪获取布尔用户输入？

4 个答案: