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<What is a null object, and when are they useful? ⁄ >




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If you've written code, you've probably used the value null to indicate some variable is not set. This is perfectly good, but did you know there's more to nulls than just the value null?

There is also a null object, which doesn't really have anything to do with the value null, but its purprose is similar.

How many times have you written code, which checks if a value is null, and then displays something special because of that? Have you written the very same check in more than one place in your code? A null object is an elegant solution to this.

Let's check out what exactly is a null object, and when it becomes a valuable pattern.



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