A char or System.Char is an integral type:
An integral type representing unsigned 16-bit integers with values between 0 and 65535. The set of possible values for the type corresponds to the Unicode character set.
This means that it behaves exactly like a uint16 or System.UInt16, and adding chars with the + operator therefore adds the integral values, because the + operator is not overloaded in char.
To concatenate individual chars into a string use StringBuilder.Append(char) or new String(char[]).
