I don't feel satisfied by avoiding null in OOP. Is there any alternative solution? I don't like to avoid it in this way either.
What is the best possible way to handle it?
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5don't let things be NULL?!? – Mitch Wheat Dec 10 '14 at 07:27
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1Why are you trying to avoid null values? Null isn't a bad thing. – Mark Madej Dec 10 '14 at 07:27
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4consider Optional (Java 8) – Eran Dec 10 '14 at 07:28
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3[Guava optional: Using and avoiding null](https://code.google.com/p/guava-libraries/wiki/UsingAndAvoidingNullExplained). – Greg Kopff Dec 10 '14 at 07:28
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2You can make an object with a method body that is empty... Which is essentially the same thing with more code... – Katler Dec 10 '14 at 07:29
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How that can be achieved. Can you elaborate @Mitch Wheat. – Madhav Bhattarai Dec 10 '14 at 07:30
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The main problem with null is that it's a value to indicate the abscence of a value! – La VloZ Merrill Jul 03 '18 at 14:17
3 Answers
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Java 8 has the new Optional type which is what I think you are asking about
A container object which may or may not contain a non-null value. If a value is present,
isPresent()will return true andget()will return the value.
Elliott Frisch
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@Greg Kopff, that is a language dependent solution. Actually i want solution from design point of view. – Madhav Bhattarai Dec 10 '14 at 07:35
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1Guava has `Optional` too. This may be useful if you are still stuck with java 7. – AlexR Dec 10 '14 at 07:36
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2@user2749218 it may be language dependent, but you tagged the question with Java... – Tom Jonckheere Dec 10 '14 at 07:37
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2Something like `Optional` is not specific to Java, in fact many functional programming languages have something similar (Haskell `Maybe`, Scala `Option`, ML `Option` etc). Java 8 borrowed it from those languages. – Jesper Dec 10 '14 at 07:38
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@user2749218 The Wikipedia entry on the [Option Type](http://en.wikipedia.org/wiki/Option_type) might be helpful then. – Elliott Frisch Dec 10 '14 at 07:40
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Although you don't like it, the Null Object Pattern is one of the best ways to avoid null. Also never return null when you could return an empty list.
Tom Jonckheere
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3Most often seen example of the null object pattern is the empty string "". Use it when you have to say something but you want to say nothing : ) – candied_orange Dec 10 '14 at 07:41
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I favour adding a static class property of Empty. This returns a specific value for the object which can be compared against - like string.Empty in .NET
kidshaw
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