Re: [elisp]How to ask and provide a Default value?

[Kevin Rodgers]

FKtPp@Office ;) wrote:
> Kevin Rodgers <ihs_4664@yahoo.com> writes:
>>(defun foo (number)
>>   (interactive "nNumber: ")
>>   (message "number=%d" number))
>>
>>When I type `M-x foo RET RET' on Emacs 19.34, I get an "End of file
>>during parsing" error.  When I type that on Emacs 21.3, I get a
>>transient "Please enter a number." Message, then the prompt is
>>redisplayed.
>
> Thank you. I got it too :)
>
>>So evidently Emacs does not provide a default for the `n' character
>>code.
>
> But, I still don't know how to use the default character description
> :P Would u please give me a sample?

The `b' character code, which is used to return an existing buffer, does
provide a default (the current buffer):

(defun foo (buffer)
  (interactive "bBuffer: ")
  (message "buffer=%s" buffer))

--
Kevin Rodgers