java scanner multiple validation

Question

I want to validate my user input from Scanner class.

validate it is an integer as well as it must be within the range of [6000, 6999]

        while(!in.hasNext("\\d+")) {
            System.out.println("<Error: Enter numbers only!>");
            System.out.println("Enter postal code :");
            in.nextLine();
        }
        postalCode = in.nextInt();
        in.nextLine();

How do I add in the validation to check if its within the range [6000, 6999]?

EDITED tried this and this is the output. it stop after that

Enter postal code :

d

Error: Enter numbers only!

Enter postal code :

1

Error: Postal code must be betwen 6000-6999 only!

Enter postal code :

1000

            System.out.println("Enter postal code :");
            while(!in.hasNext("\\d+"))
            {
                System.out.println("<Error: Enter numbers only!>");
                System.out.println("Enter postal code :");
                in.nextLine();
            }
            postalCode = in.nextInt();
            while(postalCode < 6000 || postalCode > 6999)
            {
                System.out.println("<Error: Postal code must be betwen 6000-6999 only!>");
                System.out.println("Enter postal code :");
                postalCode = in.nextInt();
                while(!in.hasNext("\\d+"))
                {
                    System.out.println("<Error: Enter numbers only!>");
                    System.out.println("Enter postal code :");
                    in.nextLine();
                }
            }
            in.nextLine();

`if (postalCode >= 6000 && postalCode <= 6999) { // Do stuff } else { // Get another value }` — ManoDestra, Jun 03 '16 at 16:42

score 2 · Accepted Answer · answered Jun 03 '16 at 16:57

2

You need a new while loop. Say postalCode = in.nextInt();, then a new loop while(postalCode < 6000 || postalCode > 6999), lastly prompt the user for a new value.

postalCode = in.nextInt();
while(postalCode < 6000 || postalCode > 6999) {
   System.out.println("Need a number between 6000 and 6999")

   //... revalidate that it is an integer

   postalCode = in.nextInt();
}

answered Jun 03 '16 at 16:57

Orin

890
5
16

please see my original post, edited – Ben Yap Jun 03 '16 at 17:07
Okay, it works, i shift the postalCode = in.nextInt(); to the end.. after revalidation – Ben Yap Jun 03 '16 at 17:11

java scanner multiple validation

1 Answers1