List Contents Compaison

I'm trying to find a way of comparing the contents of a list to see if all the items are of the same value.

e.g: '(2 3 2 2 2)

This is obviously numeric, however it would be good if it worked on a list of text too

Is there an efficient way of doing it?

The only way I can think of doing it is with the following:

(defun c:test ( / a b c i)
(setq a '(2 2 3))
(setq b (car a))
(setq c 0) 
(setq i 1)
(repeat (-(length a)1)
	(if (/= b (nth i a))
	  (setq c 1)
	  )
  (setq i (1+ i))
)
(if (eq c 0)
 (princ "\nEqual")
 (princ "\nNot Equal")
)  
(princ)
)

But I bet there's a better way

search for vl-every :-)

http://www.cadtutor.net/forum/showthread.php?85929-vl-every

http://help.autodesk.com/view/ACD/2016/ENU/?guid=GUID-8BF61C9E-1382-4168-A778-FEA394A361CC

(setq lst1 (list 1 1 1) lst2 (list 1 2 3))

(vl-every '= lst1 (cdr lst1))

(vl-every '= lst2 (cdr lst2))

gr. Rlx

Thanks for that Rix, I'm not too hot on VL functions & never heard of vl-every

There were one or two errors in my code above, since amended

Thanks for that Rix, I'm not too hot on VL functions & never heard of vl-every

 

There were one or two errors in my code above, since amended

till a couple of years ago neither did I but it really pays of to invest (vl-)some time in these functions

gr. Rlx

Try:

(apply '= '(2 2 3))

Try:

 

(apply '= '(2 2 3))

..........

Excellent Tharwat, thank you. One simple line of code replaces about 9 lines in my code. It does make me wonder how many AutoLISP functions are an amalgam of other functions though

You're most welcome.