How could I assign key binding for `C-=`

Question

In general I have key bindings as follows:

(define-key isearch-mode-map (kbd "C-h") 'isearch-del-char)

Now I want to define a key binding for C-= (Control plus equal sign, which is next to Backspace on my keyboard); where it does not work.

Is it possible to do it?

Answer 1

Without more context, the direct answer to "is it possible to generate a keybinding for C-=" is "Yes".

For example,

(global-set-key (kbd "C-=") (lambda () (interactive) (message "Hello world!")))

There are many other ways. For instance, my init contains the following use-package definition:

(use-package expand-region
  :ensure t
  :bind (("C-=" . er/expand-region)
         ("C-+" . er/contract-region)))

Both of these define global keybindings.

Key map specific bindings can be defined like you state in the question. An example of this, again taken from my init, defines the <insert> key to insert an Org structure template only for buffers with Org mode enabled:

(define-key org-mode-map (kbd "<insert>") 'org-insert-structure-template)