Question

Write a java program called allDigitsOdd that returns whether every digit of a positive integer is odd. Return true if the number consists entirely of odd digits (1, 3, 5, 7, 9) and false if any of its digits are even (0, 2, 4, 6, 8). For example, the call allDigitsOdd(135319) returns true but allDigitsOdd(9145293) returns false.

Answer 1

Answer:

public class Digits

{

   public static boolean allDigitsOdd(int num)

   {

       boolean flag=true;

       int rem;

       while(num>0)

       {

           rem=num%10;

           num=num/10;

           if(rem%2==0)    // if a even digit found immediately breaks out of loop

           {

               flag=false;

               break;

           }

       }

       return flag;     //returns result

   }

   public static void main(String args[])

   {

       System.out.println(allDigitsOdd(1375));    //returns true as all are odd digits

   }

}

OUTPUT :

true

Explanation:

Above program has 2 static methods inside a class Digits. Logic behind above function is that a number is divided by 10 until it is less than 0. Each time its remainder by 0 is checked if even immediately breaks out of the loop.