This function prints data to the server where a client is connected to.
It prints numbers as a sequence of digits. Each digit is an ASCII character (e.g. the number 123 is sent as the three characters '1', '2', '3').
data: the data to print (char, byte, int, long, or string)
*base (optional): the base in which to print numbers: DEC for decimal (base 10), OCT for octal (base 8), HEX for hexadecimal (base 16).
It returns a byte containing the number of bytes written.