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* Elisp - Determine if variable is nil
@ 2021-01-30 14:16 jai-bholeki
  2021-01-30 14:57 ` moasenwood--- via Users list for the GNU Emacs text editor
  2021-01-30 15:02 ` Jean Louis
  0 siblings, 2 replies; 4+ messages in thread
From: jai-bholeki @ 2021-01-30 14:16 UTC (permalink / raw)
  To: Help Gnu Emacs

How can I check if a variable is nil?




^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: Elisp - Determine if variable is nil
  2021-01-30 14:16 Elisp - Determine if variable is nil jai-bholeki
@ 2021-01-30 14:57 ` moasenwood--- via Users list for the GNU Emacs text editor
  2021-01-30 15:03   ` jai-bholeki
  2021-01-30 15:02 ` Jean Louis
  1 sibling, 1 reply; 4+ messages in thread
From: moasenwood--- via Users list for the GNU Emacs text editor @ 2021-01-30 14:57 UTC (permalink / raw)
  To: help-gnu-emacs

jai-bholeki wrote:

> How can I check if a variable is nil?

(setq some-var nil)

(unless some-var
  (message "var is nil") )

-- 
underground experts united
http://user.it.uu.se/~embe8573
https://dataswamp.org/~incal




^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: Elisp - Determine if variable is nil
  2021-01-30 14:16 Elisp - Determine if variable is nil jai-bholeki
  2021-01-30 14:57 ` moasenwood--- via Users list for the GNU Emacs text editor
@ 2021-01-30 15:02 ` Jean Louis
  1 sibling, 0 replies; 4+ messages in thread
From: Jean Louis @ 2021-01-30 15:02 UTC (permalink / raw)
  To: help-gnu-emacs

* jai-bholeki@gmx.com <jai-bholeki@gmx.com> [2021-01-30 17:34]:
> How can I check if a variable is nil?

If variable is defined then:

(null variable)

Return t if OBJECT is nil, and return nil otherwise.


Jean



^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: Elisp - Determine if variable is nil
  2021-01-30 14:57 ` moasenwood--- via Users list for the GNU Emacs text editor
@ 2021-01-30 15:03   ` jai-bholeki
  0 siblings, 0 replies; 4+ messages in thread
From: jai-bholeki @ 2021-01-30 15:03 UTC (permalink / raw)
  To: moasenwood; +Cc: help-gnu-emacs

When using pcase, do I need parenthesis around
dfv-break-comments-state?

(pcase dfv-break-comments-state

(pcase (dfv-break-comments-state)




> Sent: Sunday, January 31, 2021 at 2:57 AM
> From: "moasenwood--- via Users list for the GNU Emacs text editor" <help-gnu-emacs@gnu.org>
> To: help-gnu-emacs@gnu.org
> Subject: Re: Elisp - Determine if variable is nil
>
> jai-bholeki wrote:
>
> > How can I check if a variable is nil?
>
> (setq some-var nil)
>
> (unless some-var
>   (message "var is nil") )
>
> --
> underground experts united
> http://user.it.uu.se/~embe8573
> https://dataswamp.org/~incal
>
>
>



^ permalink raw reply	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2021-01-30 15:03 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2021-01-30 14:16 Elisp - Determine if variable is nil jai-bholeki
2021-01-30 14:57 ` moasenwood--- via Users list for the GNU Emacs text editor
2021-01-30 15:03   ` jai-bholeki
2021-01-30 15:02 ` Jean Louis

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