Prints data, followed by a newline, to all the clients connected to a server. Prints numbers as a sequence of digits, each an ASCII character (e.g. the number 123 is sent as the three characters ‘1’, ‘2’, ‘3’).
data (optional): 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).
println() will return the number of bytes written, though reading that number is optional