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 Abstract Members

Posted by chanjong kim
chanjong kim
2,315 Points

i have no clue

I made SequenceDetector.Scan method as an abstract as I was told, but it throws an error. I have no clue to fix it.

RepeatDetector.cs 
namespace Treehouse.CodeChallenges
{
    public class RepeatDetector : SequenceDetector
    {
        public override string Description => "Detects repetitions";

        public override bool Scan(int[] sequence)
        {
            LastScannedSequence = sequence;

            if(sequence.Length < 2)
            {
                return false;
            }

            for(int i = 1; i < sequence.Length; ++i)
            {
                if(sequence[i] == sequence[i-1])
                {
                    return true;
                }
            }

            return false;
        }
    }
}
SequenceDetector.cs 
namespace Treehouse.CodeChallenges
{
    public abstract class SequenceDetector
    {
        public virtual string Description => "";

        public int[] LastScannedSequence { get; protected set; }

        public abstract bool Scan(int[] sequence)
        {
            LastScannedSequence = sequence;
            return true;
        }
    }
}

1 Answer

Steven Parker
Steven Parker
231,268 Points
Steven Parker
Steven Parker
231,268 Points

You correctly changed the designation, but an abstract class definition also has no body.

chanjong kim
chanjong kim
2,315 Points

Yes, that is what I got from an error. Acutually I don't quite get what it says. Does it mean that 

 public abstract bool Scan(int[] sequence)
        {
            LastScannedSequence = sequence;
            return true;
        }

should be like this?
 public abstract bool Scan(int[] sequence)
        {

        }
Steven Parker
Steven Parker
231,268 Points
Steven Parker
Steven Parker
231,268 Points

That would stil be a body, just an empty one. For no body at all:

 public abstract bool Scan(int[] sequence);