> [EMAIL PROTECTED] wrote:
> > Ok fantastic, I totally understand that, and if there were going to be
> > more than one thing passed, just insert $par2 = shift; on the next
> > line and then the second argument is in $par2, I assume.....right??
>
> Yes.
>
> You might also see it this way:
>
> my ($par1, $par2) = @_;
>
> The latter construct is not destructive of @_, while using shift() is. It
> usually doesn't matter.
>
Bob is giving correct, though terse answers. Subroutines receive their
arguments in @_, in the special case that a subroutine acts as a method
(aka in OOP (Object Oriented) Perl) then the first argument is either
the object/instance/referent or the class name. In *most* cases this
argument is considered different (in meaning) than the rest, because it
is tacked on to the beginning by Perl automagically, so to retrieve the
object/class and to restore the "user specified" argument list you
generally want to C<shift> it off. So you end up with,
sub method1 {
my $self = shift;
...
# now @_ contains only those arguments provided by the user
}
Along with the possibly more commonly used,
sub method2 {
my $self = shift;
my ($arg1, $arg2) = @_;
...
}
sub method3 {
my $self = shift;
my (@args) = @_;
...
}
sub method4 {
my $self = shift;
my (%args) = @_;
...
}
And finally the above iterations with the more specific...
sub method5 {
my $class = shift;
...
}
Because Perl's rules in this area are loose the same applies to
functional (non-OOP) techniques as well, though less idiomatically
(IMHO). In other words less often will you want to shift off the
arguments one at a time, or that the first argument is significantly
different (in meaning) than the others. Having said that, it is not a
rule and should not be taken as one, however can be applied when just
making a template.
Personally I would suggest adding a blank C<return> as the last line of
the sub, and possibly providing a documentation template. To me these
are more important than how you are going to accept your arguments.
http://danconia.org
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