Generally if you have a question like that, you look up the appropriate operator, statement or whatever in the docs.
Of course, I agree in general, but in this specific case, I can understand that the OP, if she or he does not know much of Perl, would not even know where to look. Also, these backslashes don't make it easy for a beginner.
But roboticus does go on to constructively address the specific case: " In this case, you could ..." OTOH, davido's response below is much more detailed and, IMHO, preferable. In any event, ++ to both from me.
And yes, those backslashes are rather eye- and brain-bezoggling; severe LTS.