NullReferenzwert

NullReferenzwert, often shortened to null reference, is a programming concept representing the absence of a value for an object. It signifies that a variable, which is expected to hold a reference to an object in memory, currently does not point to any valid object. This can occur for various reasons, such as an object not being initialized, being explicitly set to null, or an operation that should return an object failing to do so.

When a program attempts to access a member or method of a null reference, it typically results in a runtime error, commonly known as a NullPointerException or NullReferenceException, depending on the programming language. These errors are a frequent source of bugs in software development and can cause applications to crash or behave unexpectedly.

Developers often implement checks to determine if a reference is null before attempting to use it. This practice, known as null checking, helps prevent these runtime errors and ensures more robust code. Some modern programming languages and frameworks have introduced features like nullable types or optional types to handle the potential absence of a value more explicitly and safely, reducing the likelihood of null reference errors. Understanding and managing null references is a fundamental aspect of programming.