How to delete an element from a list in scheme

Question

how to delete an element from a list ex:- list=[1 2 3 4]

I have come up with some code.I think I got wrong somewhere.

 (define delete item
   (lambda (list)
   (cond
    ((equal?item (car list)) cdr list)
     (cons(car list)(delete item (cdr list))))))

Answer 1

Your code is almost correct. The item also should be a parameter, so the function may begin with like this:

(define delete
  (lambda (item list)
  ...

Also, your code needs paren around the cdr list and else in the last clause. Then, the code may be like this:

(define delete
  (lambda (item list)
    (cond
     ((equal? item (car list)) (cdr list))
     (else (cons (car list) (delete item (cdr list)))))))

Answer 2

(define (deleteItem(list item))
    (cond
    ((eq ? item (car(list)))cdr(list))
    (cons(car(list)(deleteItem(cdr list)))
    )
)