What is the difference between setq and set-variable in emacs?

emacs elisp
Nate picture Nate · Nov 29, 2010 · Viewed 8.6k times · Source

What is the difference between setq and set-variable in emacs lisp. When should I use setq and when should I set-variable.

Answer

Sean picture Sean · Nov 29, 2010

set-variable is an interactive command, meaning that you can type M-x set-variable RET to be interactively prompted for a variable name and value. setq is not an interactive command, meaning it's only suitable for writing in Emacs Lisp code. Personally, I never use set-variable in my Lisp code, only interactively, when I want to give a value to a variable that has an immediate effect on my text editing, such as (for example) setting indent-tabs-mode to t or nil.

Another difference is that setq can set multiple variables at once. For example, in my .emacs file on OS X I have:

(setq mac-command-modifier 'meta
      mac-option-modifier 'super)

set-variable can't do that.

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