In scalar context, returns the number of fields found and
               splits into the @_ array.  Use of split in scalar context is
               deprecated, however, because it clobbers your subroutine argu-
               ments.

               If EXPR is omitted, splits the $_ string.  If PATTERN is also
               omitted, splits on whitespace (after skipping any leading
               whitespace).  Anything matching PATTERN is taken to be a delim-
               iter separating the fields.  (Note that the delimiter may be
               longer than one character.)