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Null object: Difference between revisions
→Icon and Unicon: combined headers
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Just v -> "It's not Nothing; it is " ++ show v ++ "."</lang>
==
Icon/Unicon have a [[Icon%2BUnicon/Intro#null|null value/datatype]]. It isn't possible to undefine a variable.
<lang Icon>procedure main()
nulltest("a",a) # unassigned variables are null by default
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return write(name, if /var then " is" else " is not"," null.")
end</lang>
=={{header|Io}}==
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