Anger lets you know if your boundaries are being crossed. Therefore, it is positive if it drives you to think about how to act in your defense, but negative if it becomes explosive and with no room for thought.
Can or is Anger a good emotion?
Anger is sometimes necessary and even useful but it's not an emotion I'd allow to control me.
On the very fringe of my life is a woman who takes pleasure in causing trouble for anyone she dislikes (and we are many). She isn't very bright and her personality is so transparent that few people take her seriously. If I were to become angry every time she does something nasty I'd be constantly upset. Anger, in such a case, would be overkill. It's far better just to wipe her off my shoes like a lump of unwelcome doggy-do.
Anger is more useful than despair. It is a sign of passion, a spark of inner drive. Anger can get things done. But when untethered, anger is a prelude to madness... It's a thin line.
The man who is angered by nothing, cares about nothing; but the man who is angered by trifles, is an agent of destruction.
In my experience, no. But I'll just get my popcorn ready for a potential argument.
Not specifically an answer, but this may be of interest to some:
if you need to let things out then yes.
