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C# Intermediate C# Polymorphism Accessor Access Modifiers

can't solve challenge 1 of 1

Challenge Task 1 of 1

SequenceDetector now has a LastScannedSequence property. Change the access of the LastScannedSequence property so that only SequenceDetector and its subclasses can set the LastScannedSequence property. Other classes should still be able to get the last scanned sequence. Important: In each task of this code challenge, the code you write should be added to the code from the previous task. Restart Preview Get Help Check Work SequenceDetector.cs RepeatDetector.cs

1 namespace Treehouse.CodeChallenges 2 { 3 class SequenceDetector 4 { 5 public virtual string Description => ""; 6 ​ 7 public int[] LastScannedSequence { get; private set; } 8 ​ 9 public virtual bool Scan(int[] sequence) 10 { 11 LastScannedSequence = sequence; 12 return true; 13 } 14 } 15 } 16 ​

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

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

        public virtual bool Scan(int[] sequence)
        {
            LastScannedSequence = sequence;
            return true;
        }
    }
}
RepeatDetector.cs
namespace Treehouse.CodeChallenges
{
    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;
        }
    }
}

2 Answers

It just wants you to change the access level of the property from "private" to "protected" so that the property's set method can still be accessible from it's child classes. So...

Change:

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

To:

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

Does that make sense why you do that and what the challenge is asking?

Alan Mattanó
Alan Mattanó
Courses Plus Student 12,188 Points

Too easy answer. If you take out the code, the student will look and search for this "private" and change it to "protected". In any case thanks for the answer!

thank's tj