Re: program bug

On May 2, 6:16 pm, "Bill Cunningham" <nos...@[EMAIL PROTECTED]
> wrote:
> "Robert Gamble" <rgambl...@[EMAIL PROTECTED]
> wrote in message
>
> news:2d73e006-fc0d-4ed7-ae1e-43535dea6140@[EMAIL PROTECTED]
>
> >> a is not initialized, referencing its value invokes undefined
> > behavior.
>
> >>  a=fgetc(ifp);
> >>  fputc(a,ofp);
>
>     In the beginning a was declared. Is it not enough in this case to
simply
> declare an int? Or should I have done this int a=0; at the beginning of
the
> program?

You need to store a value into a variable before you use the value of
that variable, either through initialization (implicit or explicit) or
assignment.  If you don't do this then the variable may contain
garbage ("indeterminate value" in standards parlance), that garbage
may be a trap value which will invoke UB when read.  Note that the
alternative I provided does not have this problem because "a" is
assigned before its value is used.

--
Robert Gamble