In this article, we are going to learn about what is the basic difference between Interface and Abstract Class in C#.
Difference between Abstract Class and Interface
|
|
Abstract Class |
Interface |
| Keyword | Abstract keyword is used. | Interface keyword is used. |
| Constructor | Abstract class contains a constructor. | The interface doesn’t contain a constructor. |
| Provides | Abstraction doesn’t provide full abstraction. | The interface provides full abstraction. |
| Can have fields? | An abstract class can have fields. | Interface can’t have fields. |
| Multiple inheritances | Multiple inheritances are not achieved by an abstract class. | Multiple inheritances are achieved by an interface. |
| Can Inherit? | It can be inherited from another abstract class or interface. |
Only inherit from another interface, Can’t be inherited by another abstract class. |
| Access modifiers | Contain different types of access modifiers like public, private, protected, etc. | Contains only public access modifiers. |
| Performance | The performance of abstract class is faster. | The performance of the interface is slow because it acquires time to search the actual method. |
Let us understand with some examples.
Example 1
Create Interface and Abstract Class.
//interface
public interface IStudent
{
}
//abstract class
public abstract class Student
{
}
Example 2
Try to create a constructor in the Abstract class and Interface.
//abstract constructor
public abstract class Student
{
public Student()
{
Console.WriteLine("Hello i am abstract constructor");
}
}
//interface constructor
public interface IStudent
{
//It gives error
public IStudent()
{
Console.WriteLine("Hello i am interface constructor");
}
}
Example 3
Abstract class and Interface can have fields?
public abstract class Student
{
int i=10;
}
public interface IStudent
{
int i=10;//it gives compile error "Interfaces cannot contain fields"
}
Example 4
Multiple inheritances are possible in Abstract class and Interface?
public interface IStudent1
{
}
public interface IStudent2
{
}
public class StudentClass:IStudent1,IStudent2
{
}
public abstract class Student1
{
}
public abstract class Student2
{
}
public class StudentClass:Student1,Student2//it give error
{
}
Example 5
Does implementation is possible in the Abstract class and Interface?
public abstract class Student
{
public void Print1()
{
}
}
public interface IStudent
{
//gives error
void Print2()
{
}
}
That’s it.
Also, check Constructors And Its Type In C#
