How to write specify default values for function arguments?

How to write specify default values for function arguments?

[gnuist006]

I am looking for multiple ways for
specifying default values for function arguments
as you can do in C++.

thanks

Re: How to write specify default values for function arguments?

[Tony]

"gnuist006" <gnuist006@hotmail.com> wrote in message
news:b00bb831.0210011045.5f29a1b4@posting.google.com...
> I am looking for multiple ways for
> specifying default values for function arguments
> as you can do in C++.
>
> thanks

use &optional, any parameters left out will be nil.

(defun foo (required-arg &optional opt1 opt2)
 (unless opt1 (setq opt1 default-val-1))
 (unless opt2 (setq opt2 default-val-2))
 ...)

-Tony

Re: How to write specify default values for function arguments?

[Kevin Rodgers]

Tony wrote:

> "gnuist006" <gnuist006@hotmail.com> wrote in message
> news:b00bb831.0210011045.5f29a1b4@posting.google.com...
> 
>>I am looking for multiple ways for
>>specifying default values for function arguments
>>as you can do in C++.
>>
>>thanks
>>
> 
> use &optional, any parameters left out will be nil.
> 
> (defun foo (required-arg &optional opt1 opt2)
>  (unless opt1 (setq opt1 default-val-1))
>  (unless opt2 (setq opt2 default-val-2))
>  ...)


Or do it the Common Lisp way: 


(require 'cl)

(defun* foo (required-arg &optional (opt1 default-val-1) (opt2 default-val-2))
  ...)


-- 
<a href="mailto:&lt;kevinr&#64;ihs.com&gt;">Kevin Rodgers</a>