[fpc-pascal] for loop variable value reliable after loop?

Santiago A. svaa at ciberpiula.net
Mon Oct 5 12:28:16 CEST 2015

El 05/10/2015 a las 11:48, Dennis escribió:
> var i , n : integer;
> for i := 1 to 100 do begin
>    if IntArray[i] > 100 then  begin
>     n := i;
>     break;
>    end;
> end;
> writeln('The '+IntToStr(i)+' item in the array > 100');
> //can we be always sure the value i is always the same as n?
> Even when the compiler optimizes it and uses a cpu register for i
> instead of a memory location?

I remember having read somewhere that in Pascal i value is not
guaranteed after loop, although I have never found a Pascal compiler
where i<>n.
Nevertheless, you should never rely on i value after loop. It is a bad

A little off topic, maybe you should think of using a while.

While (n<=100) and (IntArray[n] <= 100)
     do inc(n);

When the final round count is not the result of a complex computation,
(like this case, 100),  it is as fast as for loop and, IMHO, clearer.


Santiago A.

More information about the fpc-pascal mailing list