Is it OK to return null Java?

Returning null is an invitation for problems, it just takes a missing null check in the calling code for chaos to happen. If your code produces a null, instead of returning it we need to suppress it somehow.

Is returning null okay?

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.

Is it okay to use null in Java?

Conclusion: No need to fear null in Java

In this article, we covered what null is, its properties in Java, and ways you can handle the infamous NullPointerException. As a convenient way to point to the absence of a value, null throws errors when developers forget to initialize their variables before calling them.

Should I return null or empty 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.

Should you 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 .

What Does Null Mean? - Intro to Java Programming

Why null is better than empty string?

Sometimes strings can be empty or NULL. The difference is that NULL is used to refer to nothing. However, an empty string is used to point to a unique string with zero length.

Why should nulls be avoided?

The Disadvantages of NULL

The database leaves room for extra bytes should the value be larger than what is stored in the field. The result is that your database might take up more hard drive storage space than if you used regular values.

Why should null values be avoided?

It's usually good practice to avoid or minimise the use of nulls. Nulls cause some queries to return results that are "incorrect" (i.e. the results won't correspond with the intended meaning of the database).

When should I use null?

Only use null if you explicitly want to denote the value of a variable as having "no value". As @com2gz states: null is used to define something programmatically empty. undefined is meant to say that the reference is not existing. A null value has a defined reference to "nothing".

Should I return null or optional?

Using an Optional instead of using null to indicate failure/no result has some advantages: It clearly communicates that "failure" is an option. The user of your method does not have to guess whether null might be returned.

Why is null a mistake?

Null is not polymorphic with any object so any function that invokes it will break the chain of subsequent calls. This has led to innumerable errors, vulnerabilities, and system crashes.

What is the alternative to returning null in Java?

Throwing an exception is another common alternative in the Java API to returning a null when, for any reason, a value can't be provided. A typical example of this is the conversion of String into an int , provided by the Integer.

Why would you use null in Java?

In Java, null is a keyword much like the other keywords public, static or final. It is just a value that shows that the object is referring to nothing. The invention of the word “null” originated to denote the absence of something. For example, the absence of the user, a resource, or anything.

Is null a good idea?

The short answer: NULL is a value that is not a value. And that's a problem.

Why do people use null?

A NULL value is a special marker used in SQL to indicate that a data value does not exist in the database.

Why do people hate NULL?

The problems with null have little to do with null pointer exceptions. The problem with null is that it puts a lot of burden on every line of code to say, “This might be null”. Effectively that doubles your work load on every line… which means that the work goes up exponentially.

When should something be not null?

The NOT NULL constraint is used to ensure that a given column of a table is never assigned the null value. Once a NOT NULL constraint has been defined for a particular column, any insert or update operation that attempts to place a null value in that column will fail.

What is the consequence of a NULL value?

For all functions except count , if all values in the expression are null, the result is null. For count , if all values in the expression are null, the result is zero.

What is the problem with NULL in Java?

Problems with the null Pointer in Java

The NullPointerException is a common bug frequently encountered by every programmer in Java. This error is raised when we try to dereference an identifier that points to nothing – this simply means that we are expecting to reach some data but the data is missing.

Why use nulls instead of default values?

You don't know when the process being recorded will end, so null is the only appropriate value; using a default value of some fake date way out in the future will cause as much trouble to program around as handling the null s and is more likely in my experience to create a problem with incorrect results being returned.

How to deal with nulls in Java?

What happens if you put a null in a string?

“A null String is Java is literally equal to a reserved word “null”. It means the String that does not point to any physical address.” In Java programming language, a “null” String is used to refer to nothing. It also indicates that the String variable is not actually tied to any memory location.

What is the difference between null and Isempty 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. An empty string is represented as "" . It is a character sequence of zero characters.

Why is null important in programming?

In computer science, a null value represents a reference that points, generally intentionally, to a nonexistent or invalid object or address. The meaning of a null reference varies among language implementations. In JavaScript, null is marked as one of the primitive values, because its behavior is seemingly primitive.

What should I return instead of null?

Several alternatives for returning null values include using null object reference types, a null object pattern, and a result type as the return type. Therefore, the recommendation is to return an empty value instead of a null to keep the code clean and error-free.