Search list for items

[etilley327KA]

What is the easiest way to search a list to see if one of multiple objects exist in the list?

Ex: list: 22 41 39 18 32 19 25

Does 18 or 23 exist in the list?

[Moshe-A]

@etilley327KA  hi,

the best of best is Lee's (LM:ListDupes)

Moshe

;; List Duplicates  -  Lee Mac
;; Returns a list of items appearing more than once in a supplied list

(defun LM:ListDupes ( l )
    (if l
        (if (member (car l) (cdr l))
            (cons (car l) (LM:ListDupes (vl-remove (car l) (cdr l))))
            (LM:ListDupes (vl-remove (car l) (cdr l)))
        )
    )
)

(LM 

[john.kaulB9QW2 · Accepted solution]

MEMBER

(setq aList '(22 41 39 18 32 19 25))

(member 18 aList)

(member 23 aList)

[paullimapa]

can do it with AutoLISP or Visual Lisp

[Kent1Cooper]

---

@etilley327KA wrote:

What is the easiest way to search a list to see if one of multiple objects exist in the list?

....

---

If all you need to know is whether or not either of them is in the list, and you don't need the list returned from the found item to the end as (member) does, and you don't need to know in what position in the list either item falls as (vl-position) reports, you can do this:

(or (member 18 aList) (member 23 aList))

That will return a simple T [True] if either one is [or both are] in the list, or nil if neither is.

[Kent1Cooper]

(or (member 18 aList) (member 23 aList))

That will return a simple T [True] if either one is [or both are] in the list, or nil if neither is.

[calderg1000]

Regards @etilley327KA 

Try this code

(defun Fnx (lx x / n)
  (foreach i lx
    (if (= i x)
      (setq n T)
    )
  )
  (if (= n t)
    (princ "The Number exists...")
    (princ "The Number does not exist...")
  )
)

;_
(setq lt '(22 41 39 18 32 19 25))
(Fnx lt 25)
;"The Number exists..."

[etilley327KA]

Thanks! My list is a list of strings so I changed it to "18" and "23", but now its always coming back true. What am I doing wrong?

[paullimapa]

Show us your lines of code show we can see where the error is

[etilley327KA]

Sorry, my bad. I see my error now. Thanks