Quick Answer: How To Return Null In Java?

What does return null mean in Java?

In Java programming, null can be assigned to any variable of a reference type (that is, a non-primitive type) to indicate that the variable does not refer to any object or array. Object. That means that null cannot be used in place of a reference to a Java object like an instance of java.

Is it good practice to return null in Java?

Returning null is usually the best idea if you intend to indicate that no data is available. An empty object implies data has been returned, whereas returning null clearly indicates that nothing has been returned.

How do you return a null array in Java?

Return an Empty Array Using new int[0] in Java If the array has a length of zero, then it does not contain any element. To return an empty array from a function, we can create a new array with a zero size. In the example below, we create a function returnEmptyArray() that returns an array of int.

How do you return a NULL in Int?

The NULL is nothing, but the (void*(0)), pointer to zero address, by convention. If your function return a pointer to something, you can return NULL. Incrementing a NULL pointer:

  1. int *p = 0, n; // OK – p initialized to NULL.
  2. p++; // Still OK – the value of p increases by sizeof( int )
  3. n = *p; // probably does not ca.
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Should I return null or throw exception?

Only throw an exception if it is truly an error. If it is expected behavior for the object to not exist, return the null. Otherwise it is a matter of preference. As a general rule, if the method should always return an object, then go with the exception.

IS NULL == NULL in Java?

== and!= The comparison and not equal to operators are allowed with null in Java. This can made useful in checking of null with objects in java.

What happens if you return null?

Returning null Creates More Work An ideal function, like an assistant cook, will encapsulate work and produce something useful. A function that returns a null reference achieves neither goal. Returning null is like throwing a time bomb into the software. Other code must a guard against null with if and else statements.

Why NULL is bad?

NULL exacerbates poor language decisions Java silently converts between reference and primitive types. Add in null, and things get even weirder. though it throws a NullPointerException when run. It’s bad enough that member methods can be called on null; it’s even worse when you never even see the method being called.

Should I return null or empty array?

Always. It is considered a best practice to NEVER return null when returning a collection or enumerable. Empty <T>() can be seen as more efficient than returning, for example, a new empty collection or array.

What does an empty ArrayList return?

The isEmpty() method of ArrayList in java is used to check if a list is empty or not. It returns true if the list contains no elements otherwise it returns false if the list contains any element. Returns: It returns True if the list list_name has no elements else it returns false.

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Is array empty Java?

Empty Array in Java An array is empty only when it contains zero(0) elements and has zero length. We can test it by using the length property of the array object.

Should I return null Kotlin?

In Kotlin, there are optional types. If you return ServiceChargeMasterList, you say to the compiler that you will never return null. should only be used in very rare cases because it tries to transform nullable types into non-nullable types and might throw a NullPointerException when invoked on null.

Can we return NULL in CPP?

The NULL return value would only be valid if you were returning a pointer to a Normal object, NULL represents a null pointer, not a null object. It seems that from your question you expect that simply adding a * after the class name will solve your problems.

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