Returning null is definitely not a domain-driven design approach. Returning null is often a violation of the fail fast programming principle. The null can appear due to some issue in the application.
Is it bad to return null 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.
Is it a good idea to 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 in Java?
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.
What does returning 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.
Can a string be null Java?
The Java programming language distinguishes between null and empty strings. An empty string is a string instance of zero length, whereas a null string has no value at all. … A null string is represented by null . It can be described as the absence of a string instance.
Should I return null or undefined?
As we already learned, every function returns undefined when no other value is returned from that function. If you really want to indicate that you are explicitly returning an empty or invalid value, then prefer returning null .
Can you return nothing in Java?
In Java, a null value can be assigned to an object reference of any type to indicate that it points to nothing. The compiler assigns null to any uninitialized static and instance members of reference type. In the absence of a constructor, the getArticles() and getName() methods will return a null reference.
Is returning undefined bad?
A function returns undefined if a value was not returned . Note: While you can use undefined as an identifier (variable name) in any scope other than the global scope (because undefined is not a reserved word), doing so is a very bad idea that will make your code difficult to maintain and debug.
How do you return an empty string in Java?
Java String isEmpty() method with example
This method returns true if the given string is empty, else it returns false. The isEmpty() method of String class is included in java string since JDK 1.6. In other words, you can say that this method returns true if the length of the string is 0.
Should I use null in Java?
Allow null only if it makes sense for an object reference to have ‘no value associated with it’. Don’t use null to signal error conditions. The concept of null exists only for reference types. It doesn’t exist for value types.
Why returning null is bad?
Getting a null value is an ambiguous for caller, because it doesn’t say whether the null is returned due to the bug or due to the fact that the order was not found in the database. Returning null is definitely not a domain-driven design approach.
How do you avoid null?
10 Tips to Handle Null Effectively
- Don’t Overcomplicate Things. …
- Use Objects Methods as Stream Predicates. …
- Never Pass Null as an Argument. …
- Validate Public API Arguments. …
- Leverage Optional. …
- Return Empty Collections Instead of Null. …
- Optional Ain’t for Fields. …
- Use Exceptions Over Nulls.
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.
Should I use null or empty string?
It depends on the domain you are working on. NULL means absence of value (i.e. there is no value), while empty string means there is a string value of zero length. For example, say you have a table to store a person’ data and it contains a Gender column.
Can we return null in catch block?
I would say don’t catch the exception if you really can’t handle it. And logging isn’t considered handling an error. Better to bubble it up to someone who can by throwing the exception. If you must return a value, and null is the only sensible thing, there’s nothing wrong with that.