Doubt in code with rand()

Question

Why is the output of this code 135?
...
for(int i=1; i<=6; i+=2);
cout << (i + rand()%1);
...

Answer 1

It is because everything modulo 1 is 0. Try to divide any number by 1 and see, what is the remainder. It is always 0, so you are basically adding 0 to your numbers 1, 3 and 5. If you put newline inside the loop, the output will be:
1
3
5

Answer 2

any number % 1 is 0 because any number is divided with 1