not

AutoCad AutoLISP Functions

 
not
 
 
 

Verifies that an item evaluates to nil

(not item) 

Typically, the null function is used for lists, and not is used for other data types along with some types of control functions.

Arguments

item

An AutoLISP expression.

Return Values

T if item evaluates to nil; otherwise nil.

Examples

Command: (setq a 123 b "string" c nil)

nil

Command: (not a)

nil

Command: (not b)

nil

Command: (not c)

T

Command: (not '())

T

See Also
    • The null function.