stackoverflow error : check if number is even or odd without % or / operator [duplicate]

Answer 1

I asked a similar question a day or two ago. Look at this post: What does this boolean return mean?

Effectively, using this notation:

private static boolean isEven(int number)
{
    return (number & 1) == 0;
}

The & is a bitwise operator. More information on them can be found here: Bitwise Operators

Answer 2

You can use a fact that every odd number have 1 at the end of its binary representation so it looks like ???????1 where ? can be either 0 or 1. Here is how you can check it with binary AND -> &

public static boolean isEven(int num) {
    return (num & 1) == 0;
}

It works like this:

for odd numbers

          ????????1 -> any odd number
          000000001 -> one
AND       ---------
result    000000001 -> one

for even numbers

          ????????0 -> any even number
          000000001 -> one
AND       ---------
result    000000000 -> zero