Electromagnet Halbach arrays

Could a set of electromagnets be arranged in a Halbach array? If so, what would happen if only half were turned on? And if polarity were reversed? I have researched thoroughly, and I found a post on Quora, but the poster’s grammar prevented me from gaining any information. To prevent this from being closed as too broad, I just want information as to whether this would work, and maybe some of the other questions I listed above.