what does return null mean in java

This means that for any type E and R, for any E o, where o == null, o If th...

This means that for any type E and R, for any E o, where o == null, o If this map permits null values, then a return value of null does not.

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Returning null is usually the best idea if you intend to indicate that no d...

Returning null is usually the best idea if you intend to indicate that no data is available. Accessing members of an empty object will not fail meaning bugs can go .. Do you put nulls in all of its values (name, address, favoriteDrink), or do . example would be the containsKey () method on a Map in Java).

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By not returning null, you'll probably misled the API client into thin...

By not returning null, you'll probably misled the API client into thinking the call was successful. to a system, you DO NOT want null objects, but instead to account for them internally. . "Must not" means must not, period.

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Compiler will complain if you do so, as shown below. int i = null . Unlike ...

Compiler will complain if you do so, as shown below. int i = null . Unlike in SQL, in Java null == null will return true, as shown below: . If it came from a function call, check the doc if it can return null and what this means.

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That means that null cannot be used in place of a reference to a Java objec...

That means that null cannot be used in place of a reference to a Java object like the return value of the method can be null because the returned value does.

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In Java, a special null value can be assigned to an object reference. NullP...

In Java, a special null value can be assigned to an object reference. NullPointerException is This means not doing things like: Some methods that don't specify that they might return null, actually do, instead of throwing an exception.

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In Java this would be the equivalent of a NullPointerException or NPE for s...

In Java this would be the equivalent of a NullPointerException or NPE for short. Kotlin's Such a chain returns null if any of the properties in it is null. of a nullable type and want to filter non-null elements, you can do so by using filterNotNull.

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Java (programming language) getResourceAsStream() could unexpectedly return...

Java (programming language) getResourceAsStream() could unexpectedly return null if the classpath is broken. In Java, what does "return value" mean?

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Handling null in Java What can we do about it and how did it happen? Just d...

Handling null in Java What can we do about it and how did it happen? Just don't return a null in all of the methods . The questionmark means: “If the variable we're calling is null, the result is null, else, call the next.

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My preference would be to never return null for a collection as I think the...

My preference would be to never return null for a collection as I think the value of being able to distinct the case of Do you mean something like holding values in Optional (I guess Guava's since we are not in Java 8)?.

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Book Effective Java 2nd edition; by Joshua Bloch; page Item . Returns null ...

Book Effective Java 2nd edition; by Joshua Bloch; page Item . Returns null if this abstract pathname does not denote a directory, or if . Moreover, writing correct code (i.e. no bugs) doesn't necessarily mean writing.

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Do you mean that you are annoyed that C++ hasn't a null keyword You se...

Do you mean that you are annoyed that C++ hasn't a null keyword You seem to be under the impression that Java directly returns your class.

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When catching a NullPointerException in Java the StackTrace doesn't le...

When catching a NullPointerException in Java the StackTrace doesn't lead you to Instead of null as return value use the NullObject pattern, or if you can't do so throw The NoNullBeyondMethodScope does NOT mean "hide null pointers".

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This caused me to check where the method comes from, what does it contain a...

This caused me to check where the method comes from, what does it contain and . Before Java 8 it was common that a method would return null in case of a By the means of encapsulation, you should have full control over the fields value.

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Hi all, I am reviewing the code and found that method returns null in the b...

Hi all, I am reviewing the code and found that method returns null in the below code. Please think as per [B]code review[/B]. Is it valid to return.

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