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

there are plugins to let you create customized text object. without installing plugins, assume your cursor is between two commas, you could do:

T,c,

or

t,c,

to simulate your ci, for di, change the above c into d

related help doc:

:h t
:h T
:h ,