Dependency Injection without any framework?

Dependency Injection without any framework

What interviewers test

• SOLID
• Architecture fundamentals

Step 1: Abstraction

public interface IMessageService
{

void Send(string message);

}

Step 2: Implementation

public class EmailService : IMessageService
{
public void Send(string message)
{

Console.WriteLine("Email: " + message);

}
}

Step 3: Injection

public class Notification
{
private readonly IMessageService _service;
public Notification(IMessageService service)
{
_service = service;
}
public void Notify(string msg)
{

_service.Send(msg);

}
}

Why this matters

• Loose coupling
• Testable code
• Swappable implementations