Try-Catch异常处理

Question

try {
    System.out.println("how many times");
    rollnumber = scanner.nextInt();
    nigh=2;
 }catch (Exception e){
    System.out.print("invalid. re-enter");
 }     
 }while (nigh==1);

它会不断打印无限多次＆＃34;无效重复输入＆＃34;

Answer 1

你进入一个无限循环，因为scanner.nextInt();不会消耗错误输入中的字符。更改catch子句，如下所示：

try {
    ... // Your code
} catch (Exception e){
    System.out.print("invalid. re-enter");
    scanner.nextLine();
}