Can you substitute or delete between commas (or any arbitrary character) in vi/vim?

Question

For example, I have text like this:

I talked to a friend, I hiked a mountain, I am working with blah blah, 

And I want to delete or substitute

Answer 1

If you are in a section like that you could use T,ct,.

Or you if you want to install a plugin like vim-argumentative allows you to use ci, and di,