Generally speaking, you are not required to identify yourself to police. However if the police have reasonable suspicion that you have committed a crime , are committing a crime, or are about to commit a crime, the police can stop you and require you to answer questions until the reasonable suspicion is dispelled. The statute quoted above is the loitering and prowling statute. This statute is often used as a catch-all by police, but it is actually very difficult to prove this offense.
Whether the police can require you to identify yourself based on reasonable suspicion or based on the the loitering and prowling statute requires very fact specific analysis..
Generally, the answer is no, you are free to ignore them and walk away. In fact, unless you ordered otherwise, walk (but don't run) away. And yes the law is broad and the charge is not only abused by the police but can be beaten. Talk to an attorney if you've been charged with this misdemeanor.