Should functions return null?

Is it OK to return null?

Returning Null is Bad Practice

The FirstOrDefault method silently returns null if no order is found in the database. There are a couple of problems here: Callers of GetOrder method must implement null reference checking to avoid getting a NullReferenceException when accessing Order class members.

Should functions return null or an empty object?

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 a function return null or undefined?

If a variable is set to null or undefined it has no value and if a function returns null or undefined then it is saying it has no value to return. This you most likely already understand. These values are actually so similar that they are considered equal when comparing with double equals ( == ).

Why is my method returning null?

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.

Should you stop returning "null"? | Functional C#

Should you return null in Java?

Java Practices->Return Optional not null. Returning a possibly- null object from a method is usually undesirable. The caller of such a method may not be aware that it can return null . If the caller has not written code to handle the null case, and a null is returned, then an error will almost always result.

Should I throw exception or return null?

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. It certainly shouldn't be a matter of preference.

Should I use null or undefined?

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 a function return undefined?

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.

Is null undefined?

Difference Between undefined and null

undefined is a variable that refers to something that doesn't exist, and the variable isn't defined to be anything. null is a variable that is defined but is missing a value.

What does return null mean?

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.

Can you return null in C?

NULL can be used if a function returns a pointer. In this case, you return an object, which means that you have to return a real, existing object. One way of doing this is to have an "ok" field in the struct that you could set in the init function, and that you could check in the caller.

Should I return null in JSON?

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.

Why null is not good?

The problem with NULL is that it is a non-value value, a sentinel, a special case that was lumped in with everything else. Instead, we need an entity that contains information about (1) whether it contains a value and (2) the contained value, if it exists. And it should be able to “contain” any type.

IS null bad?

null per se isn't bad. A type system that makes no difference between type T and type T+null is bad. Coming back to my own question a few years later, I'm now totally a convert of the Option / Maybe approach. When Tony Hoare called null a billion dollar mistake, he was talking about language design.

Can I return null in JavaScript?

JavaScript uses the null value to represent the intentional absence of any object value. If you find a variable or a function that returns null , it means that the expected object couldn't be created.

Is null and undefined same in JavaScript?

In JavaScript, undefined is a type, whereas null an object. It means a variable declared, but no value has been assigned a value. Whereas, null in JavaScript is an assignment value. You can assign it to a variable.

Why we use return false in JavaScript?

Return false statement is used to prevent something from happening. When a return false statement is called in a function, the execution of this function is stopped. If specified, a given value is returned to the function caller.

Why is null used?

Null or NULL is a special marker used in Structured Query Language to indicate that a data value does not exist in the database. Introduced by the creator of the relational database model, E. F.

Why null == undefined is true?

Both undefined and null are falsy by default. So == returns true. But when we use the strict equality operator (===) which checks both type and value, since undefined and null are of different types (from the typeof Operator section), the strict equality operator returns false.

Should I use null or undefined for react?

undefined is actually preferable to null in many cases where you want to explicitly use the default value (e.g. for an optional param or optional React prop).

Should I always throw exceptions?

Exceptions should not be the norm. They involve the creation of an additional object, so, if only from a performance standpoint, it is problematic if exceptions can occur frequently. Mixing data and control should be avoided. The alternative to throwing an exception is often returning a null value from a method.

Can we return null in catch block?

Is returning null in catch block is best practice.. Best is a relative word. If you want to swallow / disregard the exception then you would return null. i.e. you cannot do anything about the exception but still want to continue processing then this might be "best".

What does empty return mean in Java?

An empty return statement is acceptable within a method with a void return type because it doesn't return any value. class A { public void message() { System.

Why is checking for null a good practice?

It is a good idea to check for null explicitly because: You can catch the error earlier. You can provide a more descriptive error message.