Testing oddity of an integer with the modulo operator

Question

The following code snippet does not test oddity correctly:

public static boolean isOdd(int i) {    return i % 2 == 1; } 

I read in the web that I should do it the following way:

public static boolean isOdd(int i) {    return i % 2 != 0; } 

Why is this?

Answer 1

Might be because (i % 2) != 0 works for both positive and negative numbers

Answer 2

Because when i is negative --> (-1) % 2 == -1