Why can't we define a variable inside a while loop?

Question

We can do:

using (Stream s ..)

and:

for (int i ...)

Why can\'t we as well do something like:

Answer 1

There's no inherent reason why it couldn't be done - the C# designers just chose not to allow it. It works just fine in Perl, for example ("while ((my $i = NextNum()) > 0) { ... }").