Exception Handling - Absolute Java - page 529

Display 9.1 An Exception Controlled Loop

1 import java.util.Scanner;
2 import java.util.InputMismatchException;

3 public class InputMismatchExceptionDemo
4 {
5 public static void main(String[] args)
6 {
7 Scanner keyboard = new Scanner(System.in);
8 int number = 0; // to keep compiler happy
9 boolean done = false;

10 while (! done)
11 {
12 try
13 {
14 System.out.println("Enter a whole number:");
15 number = keyboard.nextInt();
16 done = true ;
17 }
18 catch (InputMismatchException e)
19 {
20 keyboard.nextLine();
21 System.out.println("Not a correctly written whole
number.");
22 System.out.println("Try again.");
23 }
24 }

If nextInt throws an exception, the
try block ends and the Boolean
variable done is not set to true .

25 System.out.println("You entered " + number);
26 }
27 }
Sample Dialogue
Enter a whole number:
forty two
Not a correctly written whole number.
Try again.
Enter a whole number:
Fortytwo
Not a correctly written whole number.
Try again.
Enter a whole number:
42
You entered 42