--- self % args

    ʸΥեޥåȡեޥåʸ(self)ǽ񼰲
    ʸ֤ޤ

    args Ǥ
       sprintf(self, *args)
    ƱǤʳξϡ
       sprintf(self, args)
    ƱǤܺ٤ sprintfեޥåȤ򻲾ȤƤ

        p "%#x"     % 10        # => "0xa"
        p "%#x,%#o" % [10, 10]  # => "0xa,012"

