9.9.\u0039\u002E (C99)\U000039\U00002E (C99)\x39\x2E (encoding-dependent)\071\056 (encoding-dependent)\u{39}\u{2E} (C++23)\x{39}\x{2E} (C++23, encoding-dependent)\o{071}\o{056} (C++23, encoding-dependent)\U00000039\U0000002E\u0039\u002E\x39\x2E (encoding-dependent)\071\056 (encoding-dependent)\u0039\u002E\u{39}\u{2E}\u0039\u002E\x39\x2E\39\2E\000039\00002E=39=2E%39%2E