Difference Between Abstract Class and Interface in C#

In object-oriented programming, few methods exist for implementing one of the fundamental programming ideas, namely, abstraction from an object. Abstraction is the procedure through which just the data necessary for the execution of a particular function are extracted while the other available data are disregarded.
Abstract class and interface in C# are used to conduct abstraction; their methods, inheritance, access modifiers, and static members are the primary distinctions between abstract class and interface in C#.

In this blog, we will learn when and how to utilize abstract classes and interfaces in C# to accomplish certain tasks.

Abstract class and interface both have advantages and disadvantages when performing the same function and generating the same result in a program. First, let's examine the difference between abstract class and interface in C#.

What is Abstract Class?

A specific form of class that cannot be instantiated is an abstract class. Abstract classes are intended to be extended by subclasses that implement or override their methods. In other words, abstract classes are implemented either partly or not at all. Abstract classes may have functionality; abstract and concrete methods can coexist in an abstract class. A fundamental distinction between an abstract class and an interface is that an abstract class may have constructors. You may construct components and provide some degree of standard functionality that must be implemented by derived classes using abstract classes.

Features:

• An abstract class cannot be instantiated.
• Abstract classes are permitted to have abstract methods and accessors.
• Abstract classes cannot be modified with the sealed modifier since the two modifiers have different semantics.

Advantages:

• Abstract class in Java is quite useful for creating concise code.
• Abstraction in Java saves code duplication.
• Abstract classes provide code reusability.

Disadvantages:

• Abstraction in Java is costly since you must sometimes handle scenarios and circumstances that are not usually required.
• In RDBMS, object-relational impedance mismatch.
• Object-relational mapping is used by frameworks such as Hibernate.

What is Interface?

An interface is just a contract; it lacks implementation. An interface may only include method declarations; method definitions are inadmissible. In addition, there cannot be any member data in an interface. An abstract class may have method declarations, fields, and constructors, but an interface may only contain method and property declarations. The classes that implement an interface must implement the interface's defined methods. Note that a class may implement several interfaces but only extend a single class. All interface members should be implemented by the class that implements it. Interfaces, like abstract classes, cannot be instantiated.

Features:

• Constants.
• Operators.
• Static constructor.
• Nested types.
• Static fields, methods, properties, indexers, and events.
• Member declarations using the explicit interface implementation syntax.
• Explicit access modifiers (the default access is public ).

Advantages:

• A key benefit of Interface in C# is that it provides a superior option for implementing multiple inheritances.
• The interface enables plug-and-play operation. Through the implementation of the Interface, total abstraction may be accomplished.
• In addition to making our code easier to maintain, we can accomplish idea loose coupling.

Disadvantages:

• When you add new members to an interface, you must implement those members in every class that implements that interface.
• Interfaces are sluggish because more in-direction is necessary to locate the appropriate method in the actual class.

Abstract Class vs. Interface

Conclusion

In conclusion, abstract classes do not enable multiple inheritances, but interfaces do. Consequently, a class may inherit from several interfaces but only one abstract class, while an interface is an empty shell containing just the method signatures. The approaches are devoid of content. The interface is ineffective. It is only a pattern.

We hope you like this article. We have begun with a quick overview of abstract class vs. interface. We also compared the benefits, drawbacks, and features of abstract class vs. interface. We have now compared abstract class vs. interface. Please let me know in the comment section if you have any trouble keeping up. Happy studying!

Related Questions

1. Why abstract class is faster than interface in C#?

A C# abstract class may have access to a function specifier. An interface in C# can only have its signature, not its implementation. An abstract class may give a full implementation. The UI is rather sluggish.

2. When should we use interface and abstract class in C#?

Abstract classes can only be used by one class. A class may implement numerous interfaces. If many implementations of the same type have the same behaviour, then it is preferable to use an abstract class. If many implementations just share methods, Interface is preferable.

3. Can we create object of abstract class in C#?

Abstract class: is a non-object-creating class (to access it, it must be inherited from another class).

4. How many interfaces can a class implement C#?

A single class may implement an unlimited number of interfaces. A class may only inherit from one additional class.