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.
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.
How do you return a null 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.
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.
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?
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 string null or empty Java?
In Java, there is a distinct difference between null , empty, and blank Strings. An empty string is a String object with an assigned value, but its length is equal to zero. A null string has no value at all.
Is Empty function in Java?
The isEmpty() method checks whether a string is empty or not. This method returns true if the string is empty (length() is 0), and false if not.
Is empty string null in 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 .
What happens if you return null in Java?
You could change the method return type to return java. lang. Integer and then you can return null, and existing code that returns int will get autoboxed. Nulls are assigned only to reference types, it means the reference doesn’t point to anything.
Why returning null is bad?
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. These extra statements add more complexity to the software.
Is null a return type?
Void functions ¶
null is not a valid return value for a void function. Attempting to use a void function’s return value simply evaluates to null , with no warnings emitted. The reason for this is because warnings would implicate the use of generic higher order functions.
Is returning NULL bad practice?
Returning Null is Bad Practice
The FirstOrDefault method silently returns null if no order is found in the database. … 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.
Can optional return null?
Optional Class is a container for an object that may contains null . With this Optional class, we can semantically told clients that a function they will use may return a null value that lead into NullPointerException .
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.