C#: Abstract
Abstract Characteristics
- Abstract classes cannot be instantiated
- Cannot be instantiated because it’s not fully implemented.
- Can contain abstract members.
Abstract Example
public abstract class Window
{
public virtual string Title { get; set; }
public virtual void Draw()
{
// code here...
}
public abstract void Open();
}
if the method marked abstract, meaning this method has no implementation, it ends with a semicolon, and there is no body defined.
To instantiate, you’ll need to derive from the class and provide an implementation for the Open method. if you don’t provide an implementation, you’ll be building another abstract class that you cannot instantiate.
Abstract Concrete Type
A class that derives from base abstract class, and provides a definition for Open, that will be a concrete type, it’s something that can instantiate.