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# Undefined Value

Value > Special Data Values > Undefined Value

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The Undefined class implements the value used in uninitialized variables and array members.

There is one distinguished instance of the Undefined class in the reserved system variable undefined .

Constructor

    undefined

EXAMPLES
    -- check to see if MyLight has a target
    if MyLight.target != undefined then
    -- distance from light to target
    dist=distance MyLight.pos MyLight.target.pos
    else
    -- distance from light to [0,0,0]
    dist=length MyLight.pos
    -- set CH_Hand1 to undefined so can test later to see if deleted
    deleteChangeHandler CH_Hand1; CH_Hand1=undefined

#### See Also

- MAXScript FAQ: What is the difference between 'undefined' and 'unsupplied' values?

- Unsupplied Value

- Special Data Values