What is Interface in C#? | Definition, Components, Pros vs Cons

The purpose of an interface is to restrict what it is that any given class does. The role of an interface is the definition of its members. The interface cannot implement the members themselves; it depends entirely on the class which inherits and implements it.

Any interface can comprise methods, events, properties, and indexers, but the interface can have only the bare signatures of it. The declaration function is the primary task of an interface – it lacks implementation and functionality. Thus, it only provides an outline of the functions of a class that inherits and implements its properties.

Key Takeaways

1. In C#, an interface is a blueprint for classes that define a set of methods, properties, and events the implementing class must implement.
2. An interface provides a way to achieve multiple inheritances in C# since a class can implement multiple interfaces.
3. An interface is a powerful tool in C# for designing flexible and extensible code that can be easily maintained and modified over time.

Different Components of an Interface in C#

A good way to understand the concept of an interface is to imagine it as an abstract class devoid of the capacity for implementation. The following points further shed light on other aspects and features of the interface in C#.

1. Since implementation has no role in the interface, it can be reused multiple times. Since it is the primary structure or blueprint on which a class is based, it can be used to create codes of different kinds but with a degree of commonality.
2. By implementing several interfaces, one can bypass the issue of C# not simultaneously supporting inheritance from numerous classes.
3. An interface is generally always fully implemented because it dictates what a class can do. It is also a great way to group classes inherited from the same interface. The interface also effectively enables communication between objects and methods of different classes.
4. Modifications in the behaviour of classes or their definition and functionality become simpler and easier because of the interface.
5. An interface necessarily contains only methods. It is always defined by the modifier for public access.

Advantages of Interface in C#

1. Interface makes the grouping and sorting of codes easier because of its reusability and its definition of the separate components of any class. It is also flexible enough to accommodate changes in future class definitions.
2. It can thus also be used to unravel and study the relationships between dependent class objects. At the same time, it reduces the dependency of one class on another.
3. Implementation of multiple inheritances and the loose coupling of applications is possible because of the basic characteristics of the interface in C#.
4. It is often preferable to abstract class by programmers due to this one significant advantage – while a class cannot inherit more than a single abstract class, it can do so in the case of an interface.

Disadvantages of Interface in C#

1. Implementation of multiple interfaces at once can create errors such as conflicting members. A programmer must also remember that an interface does not have too many methods because this implements all the methods by a complicated class.
2. An interface can only be used to define the common elements of a set of classes; it cannot be modified to include details specific to a few. All classes in question would then implement the details.

References

1. https://www.scientific.net/AMR.622-623.1929
2. https://dl.acm.org/doi/book/10.5555/1162257