Why result is 8 ?

Question

int y;

for(int y = 2; y <= 6; y += 2) {}

cout <<y;

Answer 1

The result being 8 is coincidence, because the y that is being outputted has not been initialized before and therefore has some garbage value that was stored in that memory cell before.
The loop parameter y is only a local variable and doesn't actually affect the previously declared y, it has its own scope limited to the loop's body.

Answer 2

Yes, I understand now