Null object: Difference between revisions
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→{{header|Perl}}: add Perl 6 |
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Confusingly, there is also <code>NSNull</code>, a singleton class with one value, <code>[NSNull null]</code>, used as a dummy object to represent the lack of a useful object. This is needed in collections like arrays and dictionaries, etc., because they do not allow <code>nil</code> elements, so if you want to represent some "empty" slots in the array you would use this. |
Confusingly, there is also <code>NSNull</code>, a singleton class with one value, <code>[NSNull null]</code>, used as a dummy object to represent the lack of a useful object. This is needed in collections like arrays and dictionaries, etc., because they do not allow <code>nil</code> elements, so if you want to represent some "empty" slots in the array you would use this. |
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=={{header|Objeck}}== |
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In Objeck, "Nil" is a value of every reference type. |
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<lang Objeck> |
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# here "object" is a reference |
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if(object = Nil) { |
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"object is null"->PrintLine(); |
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} |
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</lang> |
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=={{header|OCaml}}== |
=={{header|OCaml}}== |
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