A Little example will probably help you best:
I have to say it though. Don;t use em. They are junk... Nothing but junk... Like little pieces of chewing gum under a chair it is just something that is C++. Nobody wants it there, nobody likes it there and nobody understands why they put it there.....
// This Code Comes Straight From:
// Sams Teach Yourself C++ in 21 Days 3rd Edition
// Jesse Liberty
int counter = 0;
if(counter < 5)