List Manipulation in LISP
In this article, we will discuss List manipulation in LISP. The list is a data structure that can store elements of multiple data type
we can create a list by using the list function
Syntax:
(list element1 element2 .................. element n)
List manipulating functions are used to manipulate and return the list of elements
1. car() Function:
This function is used to display the first element in the list
Syntax:
(car '(element1 element2 ........... element n))
Example:
Lisp
; list of integer elements
(write ( car '( 1 2 3 4 5 )))
(terpri)
; list of characters
(write ( car '(a b)))
(terpri)
|
Output:
1
A
2. cdr() Function:
This function is used to display the list of all elements excluding the first element
Syntax:
(cdr '(element1 element2 ........... element n))
Example:
Lisp
; list of integer elements
(write ( cdr '( 1 2 3 4 5 )))
(terpri)
; list of characters
(write ( cdr '(a b)))
(terpri)
|
Output:
(2 3 4 5)
(B)
3.cons() FUnction:
This function will take two items. one is a value and another is the list. This will insert the value into first place in the list and returns the new list
Syntax:
(cons 'value '(list_of_elements)))
where,
- value is the element to be inserted
- list_of_elements is the list of elements
Example:
Lisp
; list of integer elements
;insert 100
(write (cons '100 ' ( 1 2 3 4 5 )))
(terpri)
; list of characters
;insert a
(write (cons 'a ' (b c d e f)))
(terpri)
|
Output:
(100 1 2 3 4 5)
(A B C D E F)
4. list() Function:
This function will take multiple lists and display it
Syntax:
(list 'list1 'list2 ........ 'listn)
Example:
Lisp
;two lists and one variable
(write ( list '100 ' ( 1 2 3 4 5 ) '(g e e k s)))
(terpri)
|
Output:
(100 (1 2 3 4 5) (G E E K S))
5. append() Function:
This function will append the two or multiple lists.
Syntax:
(append'list1 'list2 ........ 'listn)
Example:
Lisp
;consider two lists and append
(write ( append '(1 2 3 4 5) ' (g e e k s)))
(terpri)
;consider three lists and append
(write ( append '(10 20) ' ( 20 30 45 ) '(a s d)))
(terpri)
|
Output:
(1 2 3 4 5 G E E K S)
(10 20 20 30 45 A S D)
6. last() Function:
This function returns the list that contains the last element in the list
Syntax:
(last 'list)
Example:
Lisp
;consider a list and get last element
(write (last '( 1 2 3 4 5 ) ))
(terpri)
;consider a list and get last element
(write (last '( 10 20 ( g e e k s))))
(terpri)
|
Output:
(5)
((G E E K S))
7. member() Function:
This function is used to return the list based on members given.
It will take two arguments:
- The first argument will be the value.
- The second argument will be the list.
If the value is present in the list, then it will return the list
Otherwise, NIL is returned.
Syntax:
(member 'value 'list )
Example:
Lisp
;consider a list with 1 as member
(write ( member '1 ' ( 1 2 3 4 5 ) ))
(terpri)
;consider a list with 10 as member
(write ( member '10 ' ( 1 2 3 4 5 ) ))
(terpri)
|
Output:
(1 2 3 4 5)
NIL
8. reverse() Function:
This function reverses the list and returns the reversed list
Syntax:
(reverse 'list)
Example:
Lisp
;consider a list and reverse
(write ( reverse '( 1 2 3 4 5 ) ))
(terpri)
;consider a list nnd reverse
(write ( reverse '(g e e k s) ))
(terpri)
|
Output:
(5 4 3 2 1)
(S K E E G)
Last Updated :
22 Nov, 2021
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