how to catch input exception for a scanner

Asked Apr 04 '22 at 14:58

Active Apr 04 '22 at 15:06

Viewed 40 times

I need to scan a number and then sort it in a list. How can i make the program ignore if a user types in letters instead of a number. it throws

Exception in thread "main" java.util.InputMismatchException.

code:

public static void InsertionSort() {

        LinkedList<Integer> list = new LinkedList<>();
        Scanner scan = new Scanner(System.in);
        
        int x=-2;
        while(x!=-1)
        {   
            System.out.println("type a number to place in a sorted list");
            x=scan.nextInt();
        }
        scan.close();
    }

edited Apr 04 '22 at 15:01

OneCricketeer

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asked Apr 04 '22 at 14:58

meytal

2

Have you learned about try-catch? – OneCricketeer Apr 04 '22 at 15:01
1

`nextInt()` expects an int, so you can try to use `next()` instead, that returns a String. Then check if the String is an int before continuing. Otherwise ignore it or throw an exception – Bentaye Apr 04 '22 at 15:03
See "example 1" in the given link. It gives you the tools you need. – Tom Apr 04 '22 at 15:05
Use scan.hasNextInt() and check if true – DCR Apr 04 '22 at 15:08

how to catch input exception for a scanner

0 Answers0