How do I test if an object is null again?-VBForums
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Thread: How do I test if an object is null again?

  1. #1

    Thread Starter
    Hyperactive Member capsulecorpjx's Avatar
    Join Date
    May 2005
    Renton, WA

    How do I test if an object is null again?

    I thought IsNull was used to see if an object was never set or set to "nothing" but it doesn't work:

    Dim test as node 'Node is a linked list node class
    if isnull(test) then
    msgbox "null"
    msgbox "not null"
    For me, "Not Null" always comes up.

    How can I test if an object is nothing/null/not set?
    "I like to run on treadmills, because at least I know I'm getting nowhere."
    - Me

  2. #2
    Head Hunted anhn's Avatar
    Join Date
    Aug 2007

    Re: How do I test if an object is null again?

    If test Is Nothing Then '-- it was not set
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  3. #3
    PowerPoster Ellis Dee's Avatar
    Join Date
    Mar 2007
    New England

    Re: How do I test if an object is null again?

    Null isn't the "variable hasn't been initialized" value, but rather "this datapoint doesn't exist so ignore it in aggregate SQL calculations."

    To identify whether a variable has been initialized is different for variants and objects:

    If IsEmpty(Variant) Then ' Variant variable was not initialized

    If (Object Is Nothing) Then ' Object variable was not initialized

    There's also IsMissing(), which is used to check if Optional parameters of type Variant were sent.

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