  In this paper, we study the complementary dual codes in more general setting
(which are called Galois LCD codes) by a uniform method. A necessary and
sufficient condition for linear codes to be Galois LCD codes is determined, and
constacyclic codes to be Galois LCD codes are characterized. Some illustrative
examples which constacyclic codes are Galois LCD MDS codes are provided as
well. In particular, we study Hermitian LCD constacyclic codes. Finally, we
present a construction of a class of Hermitian LCD codes which are also MDS
codes.
