You can (usually) easily tell what class an object is blessed into by using one of many fine dumpers; I like Data::Dump, but it's not core; Data::Dumper is core.

c:\@Work\Perl\monks>perl -wMstrict -le
"use 5.014;
 ;;
 package Foo {
   sub defaults {
     return { 'default' => 'zing' };
     }
   sub new {
     my $class = shift;
     my ($hr_args) = @_;
     my $obj = { %{ $class->defaults }, %{ $hr_args || {} } };
     return bless $obj => $class;
     }
   sub show {
     my $self = shift;
     print qq{@{[ %$self ]} @_};
     }
   }
 ;;
 package Bar {
   use parent -norequire, qw(Foo);
   sub show {
     my $self = shift;
     $self->SUPER::show('from ' . __PACKAGE__, @_);
     }
   }
 ;;
 my $b = Bar->new({ 'hi' => 'there' });
 $b->show('zoot');
 ;;
 use Data::Dump qw(dd);
 ;;
 dd $b;
"
hi there default zing from Bar zoot
bless({ default => "zing", hi => "there" }, "Bar")
[download]

Update: Per kevbot's comment:   Addition to code posted above:

...
print ref $b;
[download]

Bar
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One can also determine the class using the ref function.

If the referenced object has been blessed into a package, then that package name is returned instead.