How does odd and even output work in this code?

Question

public static boolean isOddEven(int num){

return (num < 10) ? true : (num < 100) ? (num % 2 == num / 10 % 2) : (num % 2 == num / 10 % 2) && isOddEven(num / 10);

}

Answer 1

you can just use x % 2 == 0 to check if x is even (true) or odd (false)

Answer 2

this code check if all digits in number are same odd or same even, so
isOddEven(13579); //true
isOddEven(24680); //true

code process number by separate digits by: n/10 (decimal part is lost then) and check last digit if is even by: n%2
as same as next digit: num / 10 % 2
it uses recursion for next digit: at te end call itself
and if number is only digit it is true by default: (num < 10) ? true