listp (ANSI and GNU Common Lisp Document)

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#### 14.2.17 listp [Function]

`listp` object ⇒ generalized-boolean

#### Arguments and Values::

object—an object.

generalized-boolean—a generalized boolean.

#### Description::

Returns true if object is of type list; otherwise, returns false.

#### Examples::

     (listp nil) ⇒  true
     (listp (cons 1 2)) ⇒  true
     (listp (make-array 6)) ⇒  false
     (listp t) ⇒  false

#### See Also::

consp

#### Notes::

If object is a cons, listp does not check whether object is a proper list; it returns true for any kind of list.

     (listp object) ≡ (typep object 'list) ≡ (typep object '(or cons null))