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.
- 1 Can a function return nothing?
- 2 Is it bad practice to return null?
- 3 What is return without value in Java?
- 4 Is it good to return null in Java?
- 5 Is it possible that a function have more than one return statements?
- 6 What is returned by functions that don’t have a return statement?
- 7 Should I return null or throw exception?
- 8 Is it better to return null or empty list?
- 9 Should I return null or undefined?
- 10 What is return in Java?
- 11 What is the difference between return 0 and return 1?
- 12 What is Java void?
- 13 How do you stop returning null in Java?
- 14 Can optional be Null Java?
- 15 Why is null bad?
Can a function return nothing?
There is no such thing as «returning nothing» in Python. Every function returns some value (unless it raises an exception). If no explicit return statement is used, Python treats it as returning None .
Is it bad practice to return null?
Yes, returning NULL is a terrible design, in object-oriented world. In a nutshell, NULL usage leads to: ad-hoc error handling (instead of exceptions)
What is return without value in Java?
The return statement exits from the current method, and control flow returns to where the method was invoked. … return ++count; The data type of the returned value must match the type of the method’s declared return value. When a method is declared void, use the form of return that doesn’t return a value.
Is it good 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.
Is it possible that a function have more than one return statements?
A function may have any number of return statements each returning different values. … True, A function may have any number of return statements each returning different values and each return statements will not occur successively.
What is returned by functions that don’t have a return statement?
If a function doesn’t specify a return value, it returns None . In an if/then conditional statement, None evaluates to False.
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 it better to return null or empty list?
Always. It is considered a best practice to NEVER return null when returning a collection or enumerable. ALWAYS return an empty enumerable/collection. It prevents the aforementioned nonsense, and prevents your car getting egged by co-workers and users of your classes.
Should I return null or undefined?
Undefined typically refers to something which has not yet been assigned a value (yet). Null refers to something which definitively has no value. In that case, I would recommend returning a null. Note that a function with no specified return value implicitly returns undefined.
What is return in Java?
Java return keyword is used to complete the execution of a method. The return followed by the appropriate value that is returned to the caller. This value depends on the method return type like int method always return an integer value.
What is the difference between return 0 and return 1?
return 0 in the main function means that the program executed successfully. return 1 in the main function means that the program does not execute successfully and there is some error. … return 1 means that the user-defined function is returning true.
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 .
How do you stop returning null in Java?
A good rule of thumb is to throw an exception if element does not exist, only if your API also supports contains() (or HasSomeObject(obj) ) method. One common approach that you could consider is the Null Object Pattern.
Can optional be Null Java?
Optional is primarily intended for use as a method return type where there is a clear need to represent «no result,» and where using null is likely to cause errors. A variable whose type is Optional should never itself be null . It should always point to an Optional instance.
Why is null 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.