LPM: RE: Strict variable checking in classes?

[Rich Bowen]

Resend: Non member submission

-------- Original Message --------

From: "Braun, Thomas " <Thomas.Braun at asbury.edu>
Subject: RE: Strict variable checking in classes?
Date: Wed, 28 Mar 2001 23:23:57 -0500

One trick would be to create accessor methods, and use those.  For
example:

sub count {
	return $_[0]->{count};
}

Trying mymodule->coutn will return an error saying something to the
effect
of "can't locate method coutn via package mymodule", and you only have
to
spell it right in the subroutine :-)

You can also do nifty things like the following to set and/or return the
value (in places where this is desirable)

sub count (
	my $self = shift;
	$self->{count} = shift if (scalar(@_))
	return $self->{count};
)

Anyone else have better ideas?

Tom

ps.  I'm the giddy C++ programmer, not the shuddering one

> -----Original Message-----
> From: owner-lexington-pm-list at pm.org
> [mailto:owner-lexington-pm-list at pm.org]On Behalf Of David Hempy
> Sent: Wednesday, March 28, 2001 10:58 PM
> To: Perl Geeks
> Subject: LPM: Strict variable checking in classes?
> 
> 
> 
> I'm delving into using some object oriented approaches in a 
> perl program 
> for the first time.  Finding some really neat tricks.
> 
> It seems that all instance variables (aka class attributes) 
> are key/value 
> pairs in an anonymous hash.  This makes it really easy to 
> tote along from 
> function to function all the variables you might possibly need.  Also 
> really easy to create new instance variables on the 
> fly...something that 
> should make a C++ programmer absolutely giddy.  (or make them 
> shudder...)
> 
> Anyway, one hitch I've run into is losing the "strict" checking of my 
> variable names.  If I spend a bunch of work incrementing 
> $count and then 
> try to print $coutn, perl will fuss at me at compile time.  
> ("use strict" 
> starts every program I write)
> 
> However, the laid-back approach of hash lookups will happily 
> let me print a 
> useless $this->{coutn} after incrementing $this->{count} a 
> few thousand 
> times.  Tracking down typos like that can be a real pain.  (And a 
> shuddering C programmer now beams...)
> 
> Is this just the nature of the beast?  Are there other ways to handle 
> instance variables in a class?  I fully expect to find the answer ten 
> seconds after I send this message, so wish me luck.
> 
> -dave
> 
> 
> ps. I've ordered the OOP book that several in the group have 
> promoted...hope to have this program done before it gets here.
> 
> -- 
> David Hempy
> Internet Database Administrator
> Kentucky Educational Television - Distance Learning Division
> <hempy at ket.org> -- (859)258-7164 -- (800)333-9764
> 
>