type (AutoLISP)

Returns the type of a specified item

Supported Platforms: Windows and Mac OS

Signature

(type item)

item

Type: Varies

A symbol.

Return Values

Type: Varies or nil

The data type of item. Items that evaluate to nil (such as unassigned symbols) return nil. The data type is returned as one of the atoms listed in the following table:

Data types returned by the type function
Data type	Description
ENAME	Entity names
EXRXSUBR	External ObjectARX applications
FILE	File descriptors
INT	Integers
LIST	Lists
PAGETB	Function paging table
PICKSET	Selection sets
REAL	Floating-point numbers
SAFEARRAY	Safearray
STR	Strings
SUBR	Internal AutoLISP functions or functions loaded from compiled (FAS or VLX) files Functions in LISP source files loaded from the AutoCAD Command prompt may also appear as SUBR
SYM	Symbols
VARIANT	Variant
USUBR	User-defined functions loaded from LISP source files
VLA-object	ActiveX objects

Examples

For example, given the following assignments:

(setq a 123 r 3.45 s "Hello!" x '(a b c))
(setq f (open "name" "r"))

then

(type 'a)                   returns  SYM
(type a)                    returns  INT
(type f)                    returns  FILE
(type r)                    returns  REAL
(type s)                    returns  STR
(type x)                    returns  LIST
(type +)                    returns  SUBR
(type nil)                  returns  nil

The following code example uses the type function on the argument passed to it:

(defun isint (a)
   (if (= (type a) 'INT)    is TYPE integer?
     T                      yes, return T 
     nil                    no, return nil 
   )
)