Would you like to write a book? (About what?)

I’d like to write a book about programming. Recently, I made a blog to share my code and explanation of it. When I uploaded my codes, I realized that just knowing something and explaining it are totally different. I could sort out my thoughts and make sure whether I knew something for sure. I think that writing a book also can serve the same purpose, so I’d like to do it as well for that reason.