Topic: Global variable as next input

[Adesu]

Hi Alls,
Here my code simple,this code if you load it, I first set "last_num" variable to set to "nil",then opt variable would ask,with default 36,so I put "55".
if user reload again,the "opt" variable should display last_num with 55,but this fact it's can not display last opt variable.
Does anyone know how to revised that code,thaks for your help.

Code: [Select]

(defun c:test (/ opt)
  (setq last_num '())
  (if
    lnum
    (setq last_num 36)
    )                                    ; if
  (setq opt
(getreal
   (strcat "\nEnter number of segment < "
   (itoa last_num)
   " >: ")))             
  (if
    (= opt nil)
    (setq opt 36)
    (progn
      (setq opt (fix opt))
      (setq last_num opt)
      )                                   ; progn
    )                                     ; repeat
  (princ)
  )


[Jeff_M]

Like this?

Code: [Select]

(defun c:test (/ opt)
  (or last_num
      (setq last_num 36)
      )                                    ; if
  (setq opt
(getint
   (strcat "\nEnter number of segment < "
   (itoa last_num)
   " >: ")))             
  (if (not opt)
    last_num
    (setq last_num opt)
    )                                     ; if
  (print last_num)
  (princ)
  )


[Adesu]

Hi Jeff,
It's great and thanks for your quick reply.

Like this?

Code: [Select]

(defun c:test (/ opt)
  (or last_num
      (setq last_num 36)
      )                                    ; if
  (setq opt
(getint
   (strcat "\nEnter number of segment < "
   (itoa last_num)
   " >: ")))             
  (if (not opt)
    last_num
    (setq last_num opt)
    )                                     ; if
  (print last_num)
  (princ)
  )


[Patrick_35]

Hi

I don't understand this logic

Code: [Select]

(or last_num
      (setq last_num 36)
      )
It seems to to me that if would be more suitable than one or ?

@+

[Kerry]

Nope .. that is perfectly elegant

[CAB]

I use it alot. When you format the code it will stay on one line.

Code: [Select]

(or last_num (setq last_num 36))as opposed to

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(if last_num
  (setq last_num 36)
)

[LE]

I always liked the:

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(if (not tmp) (setq tmp "value"))

or

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(setq msg (cond (msg)
("Move")))

(setq msg (cond (msg)
("Rotate")))

(setq msg (cond (msg)
("Copy")))

(setq msg "Stretch") ;; set

(setq msg nil) ;; reset

The:

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(or ... ...)

Use it, but never liked it...

[LE]

also... before passing the default value to another variable... it can verify for example the var type output, and do the appropriate... I think

ie, making sure it is a string

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(setq msg (cond ((= (type msg) 'str) msg)
("Move")))


[Jeff_M]

Luis, I guess I got in the habit of using (or ... ...) for simple checks wasy back when I didn'k tupe tooo wel. (Hmmm, maybe that's why I still use it)
This:

Code: [Select]

(or tmp (setq tmp "value"))
is shorter (i.e. - less typing) than:

Code: [Select]

(if (not tmp) (setq tmp "value"))
yep, I'm lazy at heart.....that's one reason I started writing programs, I couldn't stand performing the same exact steps everytime time I wanted to create such & such. Huh, I said, I could write a slick little proggy to do this for me and then I could just watch the computer work. 

[LE]

yep, I'm lazy at heart.....that's one reason I started writing programs, I couldn't stand performing the same exact steps everytime time I wanted to create such & such. Huh, I said, I could write a slick little proggy to do this for me and then I could just watch the computer work. 

similar situation Jeff....

[Patrick_35]

Ok, I understood
Thanks everybody 

@+