Welcome to the Treehouse Community

Want to collaborate on code errors? Have bugs you need feedback on? Looking for an extra set of eyes on your latest project? Get support with fellow developers, designers, and programmers of all backgrounds and skill levels here with the Treehouse Community! While you're at it, check out some resources Treehouse students have shared here.

Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and join thousands of Treehouse students and alumni in the community today.

Start your free trial

C# Intermediate C# Abstraction Interfaces

Posted by Brad Price
Brad Price
18,570 Points

i am not sure how to implement this interface

namespace Treehouse.CodeChallenges { public class Increment : IUnaryOperation { IUnaryOperation.Perform(value) { return value +=; } } }

IUnaryOperation.cs 
namespace Treehouse.CodeChallenges
{
    interface IUnaryOperation
    {
        double Perform(double value);
    }
}
Increment.cs 
namespace Treehouse.CodeChallenges
{
    public class Increment : IUnaryOperation
    {
        IUnaryOperation.Perform(value)
        {
           return value +=; 
        }
    }
}

1 Answer

Steven Parker
Steven Parker
231,198 Points
Steven Parker
Steven Parker
231,198 Points

:point_right:When implementing an interface, you still follow the normal rules for methods:

  • methods defined inside the class should not be prefaced by the interface name
  • methods need a declared access (usually public)
  • methods need a declared return type (the same as the interface specification)
  • parameters need a declared type (the same as the interface specification)
  • the increment operator ("+=") needs the increment quantity on the right side