Re: Globals vs. Locals

[Uli Kusterer <witness.of.teachtext@...>]

On Aug 4, 2005, at 20:32:49, Roberto Ierusalimschy wrote:

> > which is pretty much the opposite of the major languages?
> > So far I thought it was safer if variables are local by default,  
> > [...]
>
> I am not very sure, but I think that, of the 10 most "major"  
> programming
> languages (according to http://www.tiobe.com/tpci.htm), only two  
> (Python
> and PHP) use local by default.
>
> Visual Basic, C, Java, C++, C#, and Delphy have no default,  
> although if
> you say nothing inside the function the variable can yet be global but
> cannot be local, so they seem nearer to a "global by default". Perl  
> and
> JavaScript have global by default.

That may depend on where you're actually declaring the variable.  
Variables declared inside methods, classes and functions are  
definitely local in scope in C, Java, C++ and Pascal. I'd be  
surprised if Delphi behaved differently in this regard than Pascal  
did. That variables declared outside those are global IMHO simply  
happens because that is the *only* way to declare a global in the C- 
descended languages. It's been a while since I did Pascal, but I  
think there they actually have a dedicated header section for  
globals, so there's no "automatic global" there at all.

Cheers,
-- M. Uli Kusterer
http://www.zathras.de