Your question: Can you return null in Java?

Is returning null bad Java?

Returning null is often a violation of the fail fast programming principle. The null can appear due to some issue in the application. The issue can even go to production if the developer has not implemented proper exception handling, which can help quickly detect the issue.

Can you return a null string?

null is the best thing to return if and only if the following following conditions apply: the null result is expected in normal operation. It could be expected that you may not be able to find a person in some reasonable circumstances, so findPerson() returning null is fine.

Can you return null in a void method Java?

java. lang. Void is a reference type, then the following is valid: … As a result type (a function with a return value of type Void ) it means that the function *always * return null (it cannot return anything other than null , because Void has no instances).

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.

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What happens if you return null?

Returning null Creates More Work

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.

Should I use null or empty string?

only allow nulls if you’ll take null to mean something different than an empty string. for example if you have a password field, a null value could indicate that a new user has not created his password yet while an empty varchar could indicate a blank password.

IS NOT null check Java?

“java check if not null” Code Answer’s

  • Objects. isNull(obj) //returns true if the object is null.
  • Objects. nonNull(obj) //returns true if object is not-null.
  • if(Objects. nonNull(foo) && foo. something()) // Uses short-circuit as well. No Null-pointer Exceptions are thrown.

Should API return null or empty string?

If you usually return an array, and empty array is probably a good choice. But if you usually return an object, then, IMHO, null is acceptable and may be better than an empty object. If you usually return just a string or a number, then null would probably be the preferred choice.

What is Java Lang void?

lang. Void class is a placeholder which holds a reference to a class object if it represents void keyword. It is a uninstantiable placeholder. Well, uninstantiable means that this class have a private constructor and no other constructor that we can access from outside.

Does void method return null?

Its purpose is simply to represent the void return type as a class and contain a Class<Void> public value. … Therefore, the only value we can assign to a Void variable is null.

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What is Java void?

void is a Java keyword. Used at method declaration and definition to specify that the method does not return any type, the method returns void .

What should I return instead of null?

you can usually simply return an empty object instead of null , and it will work fine, without special handling. In these cases, there’s usually no need for the caller to explicitly handle the empty case.

Is return the same as return null?

return is used to “break” out from a function that has no return value, i.e. a return type of void . return NULL returns the value NULL , and the return type of the function it’s found in must be compatible with NULL .

Should you return null or empty array?

The general rule is that null, empty string (“”), and empty (0 item) arrays should be treated the same way. Return an empty array instead of a null reference. That said, if you’re using .

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