> For the complete documentation index, see [llms.txt](https://raviram.gitbook.io/c-programing/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://raviram.gitbook.io/c-programing/oop-animals/stage-3-another-abstract-class.md).

# Stage 3: Another Abstract class

## Stage 3: Another Abstract class

### Highlights:

* The fly method needs to be better provisioned to accommodate future birds without repeating the code.
* A new class called "bird" is introduced to model a hierarchy where all birds inherit from "animal".
* The bird class has a constructor that accepts the name of the bird and passes it to the parent constructor.
* The bird class is marked as abstract, as the climb method is also an abstract concept like animal.
* Multi-level inheritance is used, with the animal class inherited by the bird class, which is inherited by the parrot class.
* The climb contract is specified in the animal and concretely implemented in the parrot.
* The fly method is only in the bird class, so any bird can inherit it, and repetition is avoided.

### Animal.cs

No change!

### Bird.cs

```csharp
namespace MyApplication.Animals;

public abstract class Bird(string name) : Animal(name)
{
    //we dont know how the climb actly looks
    
    public void Fly()
    {
        Console.WriteLine($"{Name} is Flying!");
    }
}
```

### Cat.cs

No change!

### Dog.cs

No change!

### Parrot.cs

```csharp
namespace MyApplication.Animals;

public class Parrot(string name) : Bird(name)
{    
    public override void Climb()
    {
        Console.WriteLine($"{Name} is climbing on a tree!");
    }    
}
```

### Program.cs

No change!