Abstract Class In C# - Gnomon

Abstract class can contains abstract method and non-abstract method, and abstract method cannot be private. Meanwhile, sealed can not be declared with abstract
```
public abstract class Wheel
{
 [error]abstract void Go();

 public void Fix()
 {
     Console.WriteLine("This Wheel is Fixed");
 }
}
```
class derives from abstract class have to implement all abstract method, if derived class is declared as abstract, then it can avoid implementing all the abstract methods
```
public class ConcreteWheel : Wheel
{
 public override void Go()
 {
     throw new NotImplementedException();
 }
}
```
abstract class can inherit non-abstract class ```C# public abstract class Wheel: ConcreteWheel { abstract public void Go();

public void Fix() { Console.WriteLine(“This Wheel is Fixed”); } }

public class ConcreteWheel { } ```