NullObjektMuster

NullObjektMuster is a design pattern in object-oriented programming languages that allows objects to have a common default behavior when their data is missing or has an undefined value. The concept is also known as the Null Object Pattern or Empty Reference Pattern.

In programming, a null object is an object that has been initialized to point to no valid object in a program. In many cases, this can cause errors or unexpected behavior when trying to access or manipulate its properties. The NullObjektMuster addresses this problem by providing a concrete object which is used when no valid object is available. This placeholder object typically has a default implementation that returns an empty value or a neutral state, thereby avoiding potential errors or exceptions.

The NullObjektMuster usually consists of two classes: the default object (NullObject) and a quick-result object (DefaultObject). The null object is used in situations where the usual object request fails. It does not provide any values, leading to NULL model usage. On the other hand, the default object includes the usual functionality and always returns a value.

To apply the NullObjektMuster, the following key steps are typically taken:

1. Create a NullObject class that can be used as a placeholder when no valid object is available.

2. When a request for a particular object type is made, first check if it is of the NullObject type.

3. If it is the NullObject, use it instead of the actual object to assign a default value or to implement a default behavior.

The NullObjektMuster is a common object-oriented design pattern that is known for its reliability and robustness by establishing a standardized way of handling null or undefined values in programming.