Encapsulation of an object means you should never access attributes directly but use accessors and mutators(getters and setters).

One exceedling cool way to do this which I think I can credit to someone from this site(please correct me if not) is with Autoload.

If you put the following code into your class it automagically creates get_attributename() and set_attributename() methods dynamically at runtime. So you dont have to manually write 2 methods for every attribute. If you make a typo when accessing an attribute you get a nice error message saying that no method exists.

sub AUTOLOAD {
    # AUTOLOAD object accessor/mutator method
    no strict "refs"; # allow me access to the symbol table
    my ($self,$newval) = @_;
    
    return if $AUTOLOAD =~ /::DESTROY$/o; # let perl handle its own cl
+ean up
    
    if ($AUTOLOAD =~/.*::get(_\w+)/ && $self->_accessible($1, 'read'))
+{
        my $attr_name = $1;
        *{$AUTOLOAD} = sub{ return $_[0]->{$attr_name}; }; # Creates a
+n encapsulated method in the symbol table
        return $self->{$attr_name};
    }

    # determine set or get method
    if ($AUTOLOAD =~/.*::set(_\w+)/ && $self->_accessible($1, 'write')
+){
        my $attr_name = $1;
        *{$AUTOLOAD} = sub{ return $_[0]->{$attr_name}=$_[1]; };
        return $self->{$attr_name}=$newval;
    }
    # no method for this object attribute
    die "No such method!: $AUTOLOAD";
}
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