Feedback On Code That allows only 5 digit interger input.

[Reu]

Just experimenting with the 'while' function and looking for feedback as to the quality of my coding.

 

(defun c:test (/)
 (setq count 0)
 (setq 5dig (getint "\nEnter a 5 digit number: ")) ;_Enter a 5 digit number.
 (while
   (/= count 5)
    (setq 5dig (getint "\nTry again, please enter a 5 digit number: "))
    (setq strcount (itoa 5dig)) ;_Set a variable "strcount" to string from the interger from the variable "5dig"
    (setq count (strlen strcount) ;_Count the length of characters in the variable "strcount"
    )
 )
 (princ "\nYour are the Winner!")
 (princ)
)

 

Thanks

[marko_ribar]

Maybe this topic can help you...

[fixo]

Or something like this

 
(defun 5int(/ num)
(while (not (and (or (initget 1)
      (setq num (getint "\nEnter a digits: ")))
  (if (minusp num)
    (eq 6 (strlen (itoa num)))
    (eq 5 (strlen (itoa num)))))
    )
 (princ "\nAllowed input 5 digits only..."))
     (if num num)
 )

[Lee Mac]

looking for feedback as to the quality of my coding.

 

• The variable count is initialised at zero rather than the number of digits of the integer specified by the user; hence the user will be asked to 'try again' upon correctly entering a 5-digit number:
  

Enter a 5 digit number: 12345
Try again, please enter a 5 digit number: 12345
Your are the Winner!

• If the user enters a negative number, the program incorrectly validates the input:
  

Try again, please enter a 5 digit number: -1234
Your are the Winner!

• If the user presses Enter at the prompt, the program will error since the itoa function cannot accept a null argument.
  

Try again, please enter a 5 digit number:
; error: bad argument type: fixnump: nil

• The user has no way to optionally exit the loop without pressing Esc to force an error.
  

 

• You have not declared your local variables (also known as variable localisation); to understand why this is important, see my tutorial here.
  

 

• 'You're' or 'you are' is spelt incorrectly:
  

(princ "\n[color=red]Your are[/color] the Winner!")

I would suggest the following:

(defun c:test ( / int )
   (while
       (and
           (progn
               (initget 6)
               (setq int (getint "\nEnter a 5-digit number: "))
           )
           (/= 5 (strlen (itoa int)))
       )
       (princ "\nThat wasn't 5-digits.")
   )
   (if int (princ "\nYou are the winner!"))
   (princ)
)

Now:

 

• User is not prompted again if 5-digits are entered the first time:
  

Enter a 5-digit number: 12345
You are the winner!

• User cannot enter a negative number:
  

Enter a 5-digit number: -1234
Value must be positive and nonzero.

• If the user presses Enter at the prompt, the program exits cleanly without error:
  

Command: test
Enter a 5-digit number:
Command:

• As shown above, the user can optionally exit the program cleanly by pressing Enter at the prompt, without being stuck in the loop or the program resulting in an error.