Re: What does this mean?

[Perlbotics]

in reply to What does this mean?

It's a common setter/getter idiom however with an unfortunate chosen method name setID.

'get' attribute: no argument given, so $id is undefined, current value of $self->{_id} is returned

my $id = $obj->setID(); # return current _id

'set' attribute (and 'get' new value at the same time)

 my $new_id = $obj->setID( 42 ); # updates and returns new _id 42
 # or just:   $obj->setID( 42 );

[tobyink]

I don't know if it was necessarily intended to act as a getter+setter. It's probably just a setter that happens to include a quick check to prevent people from setting the ID to undef. It happens to also return the current ID, but I'd assume that's just incidental. A method needs to return something; might as well be something vaguely useful.