How to write a fixed comment in an emacs buffer, respecting the mode?

Question

I want to write a little function to enter a fixed comment string such as the following on a new line, respecting the mode, e.g. in elisp I would like it to write

;; this is a comment

on the next line; and in C I would like it to write

/* this is a comment */

on the next line, and so on. How to do this? Maybe comment-dwim is useful but I don't know how to do it. Thank you.

Answer 1

Yes, you can use comment-dwim:

(defun this-is-a-comment ()
  (interactive)
  (move-end-of-line nil)
  (newline)
  (comment-dwim nil)
  (insert "this is a comment"))