Print 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’).
server.println()
server.println(data)
server.println(data, BASE)
data (optional): the data to print (char, byte, int, long, or string)
BASE (optional): the base in which to print numbers: BIN for binary (base 2), DEC for decimal (base 10), OCT for octal (base 8), HEX for hexadecimal (base 16).
byte
println() will return the number of bytes written, though reading that number is optional