Why did Romans create a written code of law?

Romans created a written code of law and hung it in the Forum so that all citizens could read it. This way, no one could claim to not have known the laws, and so that they could publicly discuss why certain laws were there and why some shouldn't be. I don't know if this accurately answers your question, but have a good night! : D

Basically so people wouldn't claim the laws that were already made. it was made so the society was held up better