Exception in thread "main" java.util.InputMismatchException when using Scanner

Question

I have this program to reverse the order of words, but the input is messed up. This is my output log.

1
this is a trial
Exception in thread "main" java.util.InputMismatchException
    at java.util.Scanner.throwFor(Scanner.java:864)
    at java.util.Scanner.next(Scanner.java:1485)
    at java.util.Scanner.nextInt(Scanner.java:2117)
    at java.util.Scanner.nextInt(Scanner.java:2076)
    at Store_Credit.main(Store_Credit.java:13)

Process finished with exit code 1

And, here is my code :

import java.util.Scanner;

public class Reverse_Words {

    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int N;
        N = scanner.nextInt();
        for(int i = 0; i < N; i++) {
            int h  = i+1;
            String[] s = scanner.nextLine().split(" ");
            System.out.print("Case #"+h+": ");
            for(int j = s.length-1; j >=0; j++) {
                System.out.print(s[j]+" ");
            }
            System.out.println();
        }
    }
}

`Scanner.nextInt()` consumes the number you type in but _not_ the carriage return. The return is consumed by your call to `Scanner#nextLine()`. — Tim Biegeleisen, May 27 '17 at 14:38
That exception is not thrown for the input you've shown. Another one is thrown, though. Are you really entering 1 and pressing enter when executing this? — JB Nizet, May 27 '17 at 14:39
@Tim and the codes only calls split on the carriage return, which isn't an exception — OneCricketeer, May 27 '17 at 14:40
I second cricket_007: your stack trace is for Store_Credit.java, and you've posted the code of Reverse_Words.java. — JB Nizet, May 27 '17 at 14:41
This isn't the correct class! `at Store_Credit.main`. Please show that, if you want help @Deep — OneCricketeer, May 27 '17 at 14:41
To update your question with proper code which matches stack-trace use [edit] option placed below your question (or to be more precise below tags). — Pshemo, May 27 '17 at 14:44
To reverse a string `new StringBuider("TextHere").reverse().toString()` — Tilak Maddy, May 27 '17 at 15:14
@Tilak Question wants to reverse the words not the characters — OneCricketeer, May 27 '17 at 15:28

K.Shali · Answer 1 · 2017-05-27T15:31:03.173

-1

try executing this and check if you still get errors

public static void main(String[] args) {
        @SuppressWarnings("resource")
        Scanner scanner = new Scanner(System.in);
        int n;
        System.out.println("enter number");
        n = scanner.nextInt();
        for(int i = 0; i < n; i++) {
            int h  = i+1;

            System.out.println("enter string");

            String[] s = scanner1.nextLine().split(" ");
            System.out.print(s.length);
            System.out.print("Case #"+h+": ");
            for(int j = s.length-1; j >=0; j--) {
                System.out.print(s[j]+" ");
            }
            System.out.println();
        }
    }

decrement j value in the last for loop ie., j-- (not j++)

edited May 27 '17 at 15:31

answered May 27 '17 at 15:23

K.Shali

11
2

1

The code in the question isn't throwing the mentioned errors. Having two Scanners is unnecessary – OneCricketeer May 27 '17 at 15:29
Yup you are right. I realize that. Since I wasn't getting the above said errors I wasn't exactly sure what was wrong with the code. So I gave a code that runs correctly. – K.Shali May 27 '17 at 15:34
i think i figured it out. place a scanner.nextLine() after your scanner.nextInt(). Problem is nextInt() doesnt take return. and the nextLine() takes the number n you type as well as the string you type. so adding another scanner.nextLine() helps. – K.Shali May 31 '17 at 03:49

Exception in thread "main" java.util.InputMismatchException when using Scanner

1 Answers1