hide message content when phone locked
How to hide message content when phone locked so that it cannot be seen by anyone
Question marked as
Turn off notifications for messages on the lock screen. Settings>Notifications>Messages>Show on Lock Screen. If you just want to hide the message but you're ok with seeing the sender, Settings>Notifications>Messages>Show Preview>Off.
Or, don't leave your phone where other people can pick it up and look at it. And, leave it face down on the table or desk when you're with other people.