The function EnCode (const S: a string; The Key Word) : string; 
Var 
I: Byte; 
The begin 
Setlength (Result, length (s)); 
For I:=1 to Length (s) do the begin 
Result: [I]=char (byte (s) [I] xor (key SHR 8)); 
Key:=(byte (Result [I]) + key) * c1 + c2; 
end; 
end; 

The c1 and c2 are two constants,
I don't understand is the Result: [I]=char (byte (s) [I] xor (key SHR 8)); How to turn here?
Char accounted for a byte in Delphi, in Java char of two bytes, how should do