java - 我的代码有什么问题吗？做 while 并 try catch

Question

不断出现语法错误，插入 while 表达式来完成 do 语句。它可能是一些简单的东西，比如大括号等。

{
    int num = 0;
    //flag
    boolean inputOk = false;
    Scanner s = new Scanner (System.in);

    do {            
         try {
            System.out.println("Enter a number....");
            num =s.nextInt();

            System.out.println("you entered : " + num);
            // got here then things are good
            inputOk = true;

         } catch (InputMismatchException ex) {
            System.out.println("Again please....digits only");
            // flush the scanner
            s.next();
         }

    } while (inputOk != true);
    s.close();
    System.out.println("Thank you");    
}

Answer 1

在您的代码中，您缺少 do 的结束大括号“}”。对于扫描仪，最好使用资源尝试。这是工作代码

    int num = 0;
    //flag
    boolean inputOk = false;
    try (Scanner s = new Scanner(System.in)) {
        do {

            try {
                System.out.println("Enter a number....");
                num = s.nextInt();

                System.out.println("you entered : " + num);
                // got here then things are good
                inputOk = true;

            } catch (InputMismatchException ex) {
                System.out.println("Again please....digits only");
                // flush the scanner
                s.next();

            }
        }
        while (inputOk != true);
    }
        System.out.println("Thank you");