// Zorah Fung, CSE 142
// Examples of using % 10 and / 10 to look at a number digit by digit
public class DigitMethods {
   public static void main(String[] args) {
      System.out.println(digitSum(12345)); // 15
      System.out.println(digitSum(7)); // 7
      System.out.println(digitSum(273)); // 12
      System.out.println(digitSum(9065)); // 20
      System.out.println(digitSum(48175342)); //34
      System.out.println(hasOddDigit(3)); // true
      System.out.println(hasOddDigit(2468)); // false
      System.out.println(hasOddDigit(24568)); // true
      System.out.println(allDigitsOdd(3)); // true
      System.out.println(allDigitsOdd(24568)); // false
      System.out.println(allDigitsOdd(135)); // true
   }
   
   // takes a positive number and returns the sum of its digits
   public static int digitSum(int num) {
      int sum = 0;
      while(num > 0) {
         sum += num % 10;
         num = num / 10;
      }
      return sum;
   }
   
   // takes a number and returns true if it contains an odd digit
   public static boolean hasOddDigit(int num) {
      while (num > 0) {
         int digit = num % 10;
         if (digit % 2 != 0) {
            return true;
         } 
         num = num / 10;
      }
      return false;
   }	
	
   // takes a number and returns true if it contains only odd digits
   public static boolean allDigitsOdd(int num) {
      while (num > 0) {
         int digit = num % 10;
         if (digit % 2 == 0) {
            return false;
         } 
	 num = num / 10;
      }	
      return true;
   }
}