What does it mean? \ xfe in ruby?

Question

I came across the following code and could not understand what was going on.

def self.eof_packet?(data)
  data[0] == ?\xfe && data.length == 5
end

Answer 1

?starts a literal letter .

\xlaunches hexadecimal escape .

Answer 2

The hexadecimal number of FE, which is 254

Answer 3

This is the letter of the hexadecimal character. You can also use 0xfethat also works for large numbers (e.g. 0x100) that do not fit in bytes.