Question

Possible Duplicate:
How do I compare strings in Java?

Why can’t my program use my assigned string operator to calculate the two integers? For some reason its as if the program is not accepting the input from the user.

import java.io.*;

public class IntCalc {
    public static void main (String [] args) throws IOException {
        BufferedReader kb = new BufferedReader (new InputStreamReader (System.in));

        System.out.println ("This program performs an integer calculation of your choice.");

        System.out.println ("Enter an integer: ");
        int x = Integer.parseInt (kb.readLine());

        System.out.println ("Enter a second integer: ");
        int y = Integer.parseInt (kb.readLine());

        System.out.print ("Would you like to find the sum, difference, product, quotient, or remainder of your product?: ");
        String operator = kb.readLine();

        int finalNum;

        if (operator == "sum") {
            int finalNum = (x + y);
        } else if (operator == "difference") {
            int finalNum = (x - y);
        } else if (operator == "product") {
            int finalNum = (x * y);
        } else if (operator == "remainder") {
            int finalNum = (x % y);
        }

        System.out.print ("The " + operator + " of your two integers is " + finalNum ".");
    }
}

Answer 1

You need to remove the int declarations in your if statement here. Also when comparing strings use String.equals(). Make sure too to initialise finalNum or the compiler will complain.

int finalNum = 0;

if (operator.equals("sum"))
{
   finalNum = (x + y);
}
else if (operator.equals("difference"))
{
   finalNum = (x - y);
}   
else if (operator.equals("product"))
{
   finalNum = (x * y);
}
else if (operator.equals("remainder"))
{
   finalNum = (x % y);
}

System.out.print ("The " + operator + " of your two integers is " + finalNum + ".");