Is confidence attractive

Yes it is for you and one should maintain it. However, there will be people that won't care for it and consider you egotistical; a perfectionist in many ways or a 'know it all.' As long as you handle yourself in a calm manner and aim at what you want to be confident at without putting others down then you have a good character trait. When choosing a partner in life choose someone with similar qualities of confidence so that you can converse in an equal way.