```{index} single: id_2obj (Hash::Util::FieldHash) ``` ```{index} single: Hash::Util::FieldHash::id_2obj ``` # id_2obj The registered object that has a given id. ## Synopsis ```perl use Hash::Util::FieldHash qw(id id_2obj); my $obj = id_2obj($id); ``` ## What you get back A new reference to the object whose `id` is `$id`, or `undef`. Only objects that have been used as a field hash key or passed to `register` are known; for any other id, and once the object is gone, the answer is `undef`.