22 lines
898 B
Markdown
22 lines
898 B
Markdown
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---
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layout: pattern
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title: Null Object
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folder: null-object
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categories: pattern_cat
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tags: pattern_tag
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---
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**Intent:** In most object-oriented languages, such as Java or C#, references
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may be null. These references need to be checked to ensure they are not null
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before invoking any methods, because methods typically cannot be invoked on
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null references. Instead of using a null reference to convey absence of an
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object (for instance, a non-existent customer), one uses an object which
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implements the expected interface, but whose method body is empty. The
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advantage of this approach over a working default implementation is that a Null
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Object is very predictable and has no side effects: it does nothing.
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**Applicability:** Use the Null Object pattern when
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* you want to avoid explicit null checks and keep the algorithm elegant and easy to read.
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