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AutoCAD 2025 for Mac Developer and ObjectARX
    • Customization Guide
    • DXF Reference
    • AutoLISP and DCL
      • AutoLISP: Developer's Guide
      • AutoLISP: Reference
        • Functions Reference (AutoLISP)
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            • namedobjdict (AutoLISP)
            • nentsel (AutoLISP)
            • nentselp (AutoLISP)
            • not (AutoLISP)
            • nth (AutoLISP)
            • null (AutoLISP)
            • numberp (AutoLISP)
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    null (AutoLISP)

    Verifies that an item is bound to nil

    Supported Platforms: Windows, Mac OS, and Web

    Signature

    (null item)
    item

    Type: Integer, Real, String, List, Ename (entity name), T, or nil

    An AutoLISP expression.

    Return Values

    Type: T or nil

    T if item evaluates to nil; otherwise nil.

    Examples

    (setq a 123 b "string" c nil)
    nil
    
    (null a)
    nil
    
    (null b)
    nil
    
    (null c)
    T
    
    (null '())
    T

    Related Concepts

    • Symbol-Handling Functions Reference (AutoLISP)

    Related Reference

    • not (AutoLISP)
    • boundp (AutoLISP)
    • if (AutoLISP)

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