When I do this: count = ++count; Why do i get the warning - The assignment to variable count has no effect ? This means that count is incremented and then assigned to itself or something else ? Is it the same as just ++count ? What happens in count = count++; ? Why don't I get a warning for this ?
count++
and ++count
are both short for count=count+1
. The assignment is built in, so there's no point to assigning it again. The difference between count++
(also knows as postfix) and ++count
(also known as prefix) is that ++count
will happen before the rest of the line, and count++
will happen after the rest of the line.
If you were to take apart count=count++
, you would end up with this:
count = count;
count = count+1;
Now you can see why postfix won't give you a warning: something is actually being changed at the end.
If you take apart count=++count
, you would end up with this:
count = count+1;
count = count;
As you can see, the second line of code is useless, and that's why the compiler is warning you.