Telling somebody to read the docs can be done with kindness and finesse. Remember that you haven't always been as experienced as you are today. Some people are coding without even knowing where the docs
, and are doing the best they can at it.
One aim of this site (as I understand it) is to be welcoming to everyone; that ought to include people who haven't read the documentation. Should we make someone who's learning Perl for the first time hesitant to post here for fear of being lashed because they forgot, or didn't know where to look? Even if this person had the docs available, someone reading and considering asking a question might not. We need to be considerate to them, as well.
Love justice; desire mercy.