diff options
Diffstat (limited to 'contrib/perl5/pod/perltoot.pod')
| -rw-r--r-- | contrib/perl5/pod/perltoot.pod | 39 |
1 files changed, 18 insertions, 21 deletions
diff --git a/contrib/perl5/pod/perltoot.pod b/contrib/perl5/pod/perltoot.pod index c77a971..31a7c76 100644 --- a/contrib/perl5/pod/perltoot.pod +++ b/contrib/perl5/pod/perltoot.pod @@ -111,8 +111,8 @@ by up-casing the hash keys: PEERS => [ "Norbert", "Rhys", "Phineas"], }; -And so you could get at C<$rec-E<gt>{NAME}> to find "Jason", or -C<@{ $rec-E<gt>{PEERS} }> to get at "Norbert", "Rhys", and "Phineas". +And so you could get at C<< $rec->{NAME} >> to find "Jason", or +C<< @{ $rec->{PEERS} } >> to get at "Norbert", "Rhys", and "Phineas". (Have you ever noticed how many 23-year-old programmers seem to be named "Jason" these days? :-) @@ -329,7 +329,7 @@ do more than fetch or set one particular field. sub exclaim { my $self = shift; return sprintf "Hi, I'm %s, age %d, working with %s", - $self->{NAME}, $self->{AGE}, join(", ", $self->{PEERS}); + $self->{NAME}, $self->{AGE}, join(", ", @{$self->{PEERS}}); } Or maybe even one like this: @@ -542,7 +542,7 @@ and DESTROY methods as follows: } What happens if a derived class (which we'll call Employee) inherits -methods from this Person base class? Then C<Employee-E<gt>debug()>, when called +methods from this Person base class? Then C<< Employee->debug() >>, when called as a class method, manipulates $Person::Debugging not $Employee::Debugging. =head2 Class Destructors @@ -816,7 +816,7 @@ What do we mean by the Person::new() function -- isn't that actually a method? Well, in principle, yes. A method is just a function that expects as its first argument a class name (package) or object (blessed reference). Person::new() is the function that both the -C<Person-E<gt>new()> method and the C<Employee-E<gt>new()> method end +C<< Person->new() >> method and the C<< Employee->new() >> method end up calling. Understand that while a method call looks a lot like a function call, they aren't really quite the same, and if you treat them as the same, you'll very soon be left with nothing but broken programs. @@ -1124,8 +1124,7 @@ it happens when you say If you wanted to add version checking to your Person class explained above, just add this to Person.pm: - use vars qw($VERSION); - $VERSION = '1.1'; + our $VERSION = '1.1'; and then in Employee.pm could you can say @@ -1363,7 +1362,7 @@ constructor will look like when taking this approach: package Person; use Carp; - use vars qw($AUTOLOAD); # it's a package global + our $AUTOLOAD; # it's a package global my %fields = ( name => undef, @@ -1433,8 +1432,7 @@ Here's how to be careful: package Employee; use Person; use strict; - use vars qw(@ISA); - @ISA = qw(Person); + our @ISA = qw(Person); my %fields = ( id => undef, @@ -1560,16 +1558,15 @@ Here's the whole implementation: BEGIN { use Exporter (); - use vars qw(@EXPORT @EXPORT_OK %EXPORT_TAGS); - @EXPORT = qw(gethostbyname gethostbyaddr gethost); - @EXPORT_OK = qw( - $h_name @h_aliases - $h_addrtype $h_length - @h_addr_list $h_addr - ); - %EXPORT_TAGS = ( FIELDS => [ @EXPORT_OK, @EXPORT ] ); + our @EXPORT = qw(gethostbyname gethostbyaddr gethost); + our @EXPORT_OK = qw( + $h_name @h_aliases + $h_addrtype $h_length + @h_addr_list $h_addr + ); + our %EXPORT_TAGS = ( FIELDS => [ @EXPORT_OK, @EXPORT ] ); } - use vars @EXPORT_OK; + our @EXPORT_OK; # Class::Struct forbids use of @ISA sub import { goto &Exporter::import } @@ -1661,7 +1658,7 @@ update value fields in the hash. Convenient, eh? } use Alias qw(attr); - use vars qw($NAME $AGE $PEERS); + our ($NAME, $AGE, $PEERS); sub name { my $self = attr shift; @@ -1692,7 +1689,7 @@ update value fields in the hash. Convenient, eh? return ++$AGE; } -The need for the C<use vars> declaration is because what Alias does +The need for the C<our> declaration is because what Alias does is play with package globals with the same name as the fields. To use globals while C<use strict> is in effect, you have to predeclare them. These package variables are localized to the block enclosing the attr() |
