InputMismatchException Error

[James Allen A.]

I think I matched up all my data types correctly but I'm getting the following error.

Exception in thread "main" java.util.InputMismatchException
	at java.util.Scanner.throwFor(Scanner.java:909)
	at java.util.Scanner.next(Scanner.java:1530)
	at java.util.Scanner.nextBoolean(Scanner.java:1825)
	at CointingCoins.main(CointingCoins.java:29)

Here is my code:

import java.util.ArrayList;
import java.util.Iterator;
import java.util.Arrays;
import java.util.Scanner;

public class CointingCoins {
	
	public static void main(String[] args) {
		
		int getcoinctrl = 0;
		int ordcoincount = 1;
		int coinreturn;
		boolean morecoins;
		
		ArrayList<Integer> coins = new ArrayList<Integer>();
	
		do {
	
		System.out.println("Please enter the value of the " + ordcoincount + " coin.");
		
		Scanner myScanner = new Scanner(System.in);
		
		coinreturn = myScanner.nextInt();
		
		coins.add(coinreturn);
		
		System.out.println("Would you like to add another coin value? (Y/N)");
		
		morecoins = myScanner.nextBoolean();
		
		ordcoincount++;
		getcoinctrl++;
		
		} while (morecoins);
		
		System.out.println(coins.get(0));
		
		
		
		/* public static String getOrdinalFor(int value) {
			 int tenRemainder = value % 10;
			 switch (tenRemainder) {
			  case 1:
			   return "st";
			  case 2:
			   return "nd";
			  case 3:
			   return "rd";
			  default:
			   return "th";
			 }
			}
			*/
	}

}

I can't figure this out.

[Robert Lippens]

Your stack trace shows the error emerges at line 29, which is where you have morecoins = myScanner.nextBoolean();

It states that this is an InputMismatchException, meaning that whatever the user has input cannot, in your case, be translated into a boolean value. Have you tried to have the user put in true or false? That should solve the issue.

[Maneesh Godbole]

        System.out.println("Would you like to add another coin value? (Y/N)");            
        morecoins = myScanner.nextBoolean();  

From the API docs

#hasNextBoolean()
Returns true if the next token in this scanner's input can be interpreted as a boolean value using a case insensitive pattern created from the string "true|false". The scanner does not advance past the input that matched.
nextBoolean()
Scans the next token of the input into a boolean value and returns that value. This method will throw InputMismatchException if the next token cannot be translated into a valid boolean value. If the match is successful, the scanner advances past the input that matched.

Hint:
What are the choices given to the user and what does the method expect to be able to parse to a boolean?

Drat! Robert beat me to it

[Campbell Ritchie]

And welcome to the Ranch, Robert Lippens

[James Allen A.]

Ahh I see. I didn't expect it to be that simple of a fix. I, it looks like incorrectly, remember reading that Boolean values could be true, false, yes, no, y, n, etc..

I changed my variable to a String and now use the .equals() function to ask the user for more input. I get the feeling this isn't the best way though.

import java.util.ArrayList;
import java.util.Iterator;
import java.util.Arrays;
import java.util.Scanner;

public class CointingCoins {
	
	public static void main(String[] args) {
		
		int getcoinctrl = 0;
		int ordcoincount = 1;
		int coinreturn;
		String morecoins;
		
		ArrayList<Integer> coins = new ArrayList<Integer>();
	
		do {
	
		System.out.println("Please enter the value of the " + ordcoincount + " coin.");
		
		Scanner myScanner = new Scanner(System.in);
		
		coinreturn = myScanner.nextInt();
		
		coins.add(coinreturn);
		
		System.out.println("Would you like to add another coin value? (Y/N)");
		
		morecoins = myScanner.next();
		
		morecoins.toLowerCase();
		
		ordcoincount++;
		getcoinctrl++;
		
		} while ("y".equals(morecoins) || "yes".equals(morecoins));
		
		System.out.println(coins.get(0));
		
		
		
		/* public static String getOrdinalFor(int value) {
			 int tenRemainder = value % 10;
			 switch (tenRemainder) {
			  case 1:
			   return "st";
			  case 2:
			   return "nd";
			  case 3:
			   return "rd";
			  default:
			   return "th";
			 }
			}
			*/
	}

}