Re: naming subroutine reference parameter?
Jeff Pan wrote: my (%hash,@array); sub_test(\%hash,[EMAIL PROTECTED]); has special meaning so it should be dropped when not needing particular special behavior. I can't understand for this,can u give me some examples? perldoc perlsub -- NAME(LIST); # Circumvent prototypes. NAME; # Makes current @_ visible to called subroutine. Use only when you want described side effects. -- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] http://learn.perl.org/ http://learn.perl.org/first-response
naming subroutine reference parameter?
How do you name subroutine reference parameter in perl? Naming a local or pass by value is by simply using my ($param1, $param2) = @_ ; How about by reference? I think it would be harder if I'll be using $_[0], $_[1] direct method. Is it possible? Thanks. -- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] http://learn.perl.org/ http://learn.perl.org/first-response
Re: naming subroutine reference parameter?
On Tue, 6 Sep 2005 16:12:35 +0800, Jayvee Vibar [EMAIL PROTECTED]
said:
How do you name subroutine reference parameter in perl?
Naming a local or pass by value is by simply using my ($param1, $param2)
=
@_ ;
How about by reference? I think it would be harder if I'll be using
$_[0],
$_[1] direct method.
Is it possible?
Thanks.
Passing reference as parameter to subroutine is as easy as the normal
way.And,if u pass some types of parameter such as hash,array,or handle
to subroutine,using reference instead is more safer.
for example,such below code is right:
my (%hash,@array);
sub_test(\%hash,[EMAIL PROTECTED]);
sub sub_test{
my ($hash_ref,$array_ref)[EMAIL PROTECTED];
my %hash=%$hash_ref;
my @[EMAIL PROTECTED];
do something...
}
--
Jeff Pan
[EMAIL PROTECTED]
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Re: naming subroutine reference parameter?
On 9/6/05, Jayvee Vibar [EMAIL PROTECTED] wrote:
How do you name subroutine reference parameter in perl?
Naming a local or pass by value is by simply using my ($param1, $param2) =
@_ ;
How about by reference? I think it would be harder if I'll be using $_[0],
$_[1] direct method.
Is it possible?
Those are two separate questions... you can name function parameters like so:
sub myfunc {
my %args = @_;
if ($args{debug}) { print debug!\n; }
# ...
}
myfunc(debug = 1, foo = 'bar');
And you can pass by reference by using, er, references.
#!/usr/bin/perl
use strict;
use warnings;
use Data::Dumper;
sub nosoup {
my %args = @_;
if (defined $args{soupline}
and ref $args{soupline} eq 'HASH') {
if (defined $args{nosoupfor}) {
delete $args{soupline}{$args{nosoupfor}};
}
return $args{soupline};
} else {
return ();
}
}
my %soupline = (fred=1,dave=2);
print Dumper(\%soupline);
nosoup(soupline = \%soupline, nosoupfor = 'dave');
print Dumper(\%soupline);
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Re: naming subroutine reference parameter?
Jeff Pan wrote:
Passing reference as parameter to subroutine is as easy as the normal
way.And,if u pass some types of parameter such as hash,array,or handle
to subroutine,using reference instead is more safer.
for example,such below code is right:
It is, however it could be better.
my (%hash,@array);
sub_test(\%hash,[EMAIL PROTECTED]);
has special meaning so it should be dropped when not needing
particular special behavior.
sub sub_test{
my ($hash_ref,$array_ref)[EMAIL PROTECTED];
ok.
my %hash=%$hash_ref;
my @[EMAIL PROTECTED];
This isn't needed actually and it only makes unnecessary overhead as
keys/values are copied, so you immediately lost benefit by passing by
reference.
It's better to access them directly like,
$hash_ref-{key}
$array_ref-[0]
do something...
}
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Re: naming subroutine reference parameter?
my (%hash,@array);
sub_test(\%hash,[EMAIL PROTECTED]);
has special meaning so it should be dropped when not needing
particular special behavior.
I can't understand for this,can u give me some examples?
my %hash=%$hash_ref;
my @[EMAIL PROTECTED];
This isn't needed actually and it only makes unnecessary overhead as
keys/values are copied, so you immediately lost benefit by passing by
reference.
It's better to access them directly like,
$hash_ref-{key}
$array_ref-[0]
do something...
}
This point is great,thank u.
--
Jeff Pan
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