How do you implement the factory pattern?

Question

Accepted Answer

**Factory** — create objects without specifying class.

**Basic factory:**
```csharp
public interface IAnimal
{
    string Speak();
}

public class Dog : IAnimal { public string Speak() => "Woof"; }
public class Cat : IAnimal { public string Speak() => "Meow"; }

public static class AnimalFactory
{
    public static IAnimal Create(string type) => type switch
    {
        "dog" => new Dog(),
        "cat" => new Cat(),
        _ => throw new ArgumentException()
    };
}
```

**With DI:**
```csharp
builder.Services.AddScoped<IAnimalFactory, AnimalFactory>();
```

**Key:** Factory for object creation abstraction.

C#: How do you implement the factory pattern?