Java - Coding Challenge 16 - Sum of First and Last Digit

gistfile1.txt

    public static int sumFirstAndLastDigit(int number){

        if (number < 0 ) {
            return -1;
        }

        int firstDigit = number%10;
        int lastDigit=0;
        for (int i = number; i != 0; i /= 10){
            lastDigit = i%10;
        }
        return firstDigit+lastDigit;
    }