Check whether the number is divisible by both 3 and 7, or by neither of them

Question

Got my head in spaghetti mode.

Here is the question:

(Check a number) Write a program that prompts the user to enter an integer and checks whether the number is divisible by both 3 and 7, or by neither of them, or by just one of them. Here are some sample runs for inputs, 9,21, and 25.

9 is divisible by 3 or 7, but not both 21 is divisible by both 3 and 7 25 is not divisible by either 3 or 7/

This is what I have so far. I know I'm wrong but do not think I am too far from solving the question.

public class Quest12 {

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {

        Scanner scan = new Scanner(System.in);
        System.out.println("Enter a number: ");
        int i = scan.nextInt();

        if (i % 3 == 0 ^ 7 == 0) {
            System.out.println(i + " is divisible by 3 or 7. ");
        } 
        else if (i % 3 == 0 || 7 == 0)
        {
           System.out.println(i + " is divisble by either 3 or 7. but not both "); 
        }
        if (i % 3 == 0 && 7 == 0)
        {
            System.out.println(i + " is divisble by both 3 and 7 ");
        }
    }
}

Answer 1

I would perform each modulus and store the result(s) in boolean variables. Like,

boolean mod3 = i % 3 == 0;
boolean mod7 = i % 7 == 0;
if (mod3 && mod7) {
    System.out.printf("%d is divisible by 3 and 7.%n", i);
} else if (mod3 || mod7) {
    System.out.printf("%d is divisible by 3 or 7 (but not both).%n", i);    
} else {
    System.out.printf("%d is not divisible by 3 or 7.%n", i);       
}