I have an iPhone and I blocked a number. Will messages they sent show up if I unblock them?

I have an iPhone and I blocked a number. If I unblocked the number, will I be able to see any messages or missed calls they sent while they were blocked?

Should do yes. Usually the way messages are "blocked" is just hiding them from the user who doesn't want to see them. When you unblock it may show the messages. But again, some apps completely block out messages so you won't have access. The best way to check is to unblock them.