Scanner input = new Scanner(System.in);

        System.out.println("Enter a value : ");
        String s3 = input.next();
        System.out.println("Enter another value: " );
        String s5 = input.next();

        String s = ("1= add, 2 = subtract");
        int op = Integer.parseInt(s);
        double result=0;
        switch (op) {
        case 1:
            result = addValues(s3, s5);
            break;
        case 2:
             result = subtractValues(s3, s5);
        default:
            System.out.println("Incorrect");
            break;
        }

        addValues(s3, s5);

        subtractValues(s3, s5);
    }

    private static double subtractValues(String s3, String s5)
            {
        double d1 = Double.parseDouble(s3);
        double d2 = Double.parseDouble(s5);

        double result = d1-d2;
        return result;
    }

    private static double addValues(String s3, String s5)
         {
        double d1 = Double.parseDouble(s3);
        double d2 = Double.parseDouble(s5);

        double result = d1+d2;
        return result;


    }
    }

I have the above code and its thorwing an exception of numberformatException. What is wrong with this code .. kindly help me out.

I have the above code and its thorwing an exception of numberformatException. What is wrong with this code .. kindly help me out.

Which values did you enter as input?

Edit: look closely at the following two lines of code:

String s = ("1= add, 2 = subtract");
int op = Integer.parseInt(s);

You are trying to parse the String 1= add, 2 = subtract as an int, and then get thrown a NumberFormatException in your face because that String is not a valid number.

Edited 3 Years Ago by mvmalderen

so whats the perfert way to do it now ?
i want these options to be shown..
and user should input one of the options as an integer

Print the options the user can choose from, and prompt the user to choose one of them.
Without error checking the code could look as follows:

System.out.println("1 = add, 2 = subtract");
System.out.println("pick an option> ");
int choice = Integer.parseInt(input.nextLine());
// ...

Edited 3 Years Ago by mvmalderen

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