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C# is a language in which the null object pattern can be properly implemented. This example shows animal objects that display sounds and a NullAnimal instance used in place of the C# null keyword. The null object provides consistent behaviour and prevents a runtime null reference exception that would occur if the C# null keyword were used instead.
The object pool design pattern creates a set of objects that may be reused. When a new object is needed, it is requested from the pool. If a previously prepared object is available, it is returned immediately, avoiding the instantiation cost. If no objects are present in the pool, a new item is created and returned.
Object class, the ultimate base class of all objects. This class contains the most common methods shared by all objects. Some of these are virtual and can be overridden. Classes inherit System. Object either directly or indirectly through another base class. Members Some of the members of the Object class: Equals - Supports comparisons between ...
The examples are still bad, though. The C example misses the concept entirely (the pattern requires the concept of objects, so I don't know that this pattern can be implemented in C) and while an empty C# array may exhibit similar behavior to a null object, it certainly isn't a good example of the practical use of the pattern.
Intuitively, this algorithm is an efficient solution to the problem. But if the pattern is not written carefully, it will have a data race. For example, consider the following sequence of events: Thread A notices that the value is not initialized, so it obtains the lock and begins to initialize the value.
In a software design pattern view, lazy initialization is often used together with a factory method pattern. This combines three ideas: This combines three ideas: Using a factory method to create instances of a class ( factory method pattern )
In object-oriented programming, the singleton pattern is a software design pattern that restricts the instantiation of a class to a singular instance. It is one of the well-known "Gang of Four" design patterns , which describe how to solve recurring problems in object-oriented software. [ 1 ]
The marker interface pattern is a design pattern in computer science, used with languages that provide run-time type information about objects.It provides a means to associate metadata with a class where the language does not have explicit support for such metadata.