Prompt for input using do and switch

Question

public static void main(String[] args){
    char OperatorCode;
    int answer;
    int firstOperand;
    int secondOperand;
    String inputString;
    boolean quit = false;
    Scanner inLine = new Scanner(System.in);
    do{
        System.out.print("Enter the Operator Code (A,S,M or D): ");
        inputString = inLine.nextLine();
        OperatorCode = inputString.charAt(0);
        if (OperatorCode != 'Q'){
            inputString = inputString.substring(1, inputString.length());
            Scanner string = new Scanner(inputString);
            System.out.print("Enter the First Operand: ");
            firstOperand = string.nextInt();
            System.out.print("Enter the Second Operand: ");
            secondOperand = string.nextInt();
            switch (OperatorCode){
                case 'A' : answer = (firstOperand + secondOperand);
                           System.out.println(firstOperand + " + " + secondOperand + " is " + answer);
                case 'S' : answer = (firstOperand - secondOperand);
                           System.out.println(firstOperand + " - " + secondOperand + " is " + answer);
                case 'M' : answer = (firstOperand * secondOperand);
                           System.out.println(firstOperand + " * " + secondOperand + " is " + answer);
                case 'D' : answer = (firstOperand / secondOperand);
                           System.out.println(firstOperand + " / " + secondOperand + " is " + answer);
                           break;
            }               
        } else 
              quit = true;
    }while (!quit);
} 
}

What seems to be the problem on my code? It outputs the first statement(?) fine and I can input my desired character there but when it goes to the second statement(?) ("Enter the first Operand.") I get an error which says"

"Enter the First Operand: Exception in thread "main" java.util.NoSuchElementException"

Can somebody please point out my fault?

Add `string.nextLine();` after `System.out.print("Enter the Second Operand: ");`. — ha9u63a7, Nov 04 '14 at 10:07
The lack of `break` statements at the end of each `case` is at least one problem... — Jon Skeet, Nov 04 '14 at 10:07

score 0 · Answer 1 · edited May 23 '17 at 11:49

0

This may be a problem of remaining '\n'. Maybe this question may help you : Scanner issue when using nextLine after nextXXX

edited May 23 '17 at 11:49

Community

1
1

answered Nov 04 '14 at 10:08

chipou

45
1
4

I'm afraid that that is not the problem :/ I'm still getting the error. – Rod Galangco Nov 04 '14 at 10:13

score 0 · Accepted Answer · answered Nov 04 '14 at 10:12

0

I suggest you to use string.nextLine(); instead of .nextInt(); method as it doesnt takes care of EOL while nextLine parses it

And why do you pass the string as the parameter to the scanner class here ,

Scanner string = new Scanner(inputString);

i guess it could be , (System.in)

Also add break; to your case A,S and M as John suggested

answered Nov 04 '14 at 10:12

Santhosh

8,181
4
29
56

Thank you but I still get the same error and now it added that string cannot be converted to int. – Rod Galangco Nov 04 '14 at 10:16
Oh wow. How could I have overlooked that. Thank you very much! :D – Rod Galangco Nov 04 '14 at 10:28
break; and System.in . Tho it did not need to be string.nextLine(); – Rod Galangco Nov 04 '14 at 10:52

Prompt for input using do and switch

2 Answers2