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C# Intermediate C# Polymorphism Virtual Properties

Atanu Mondal
Atanu Mondal
1,976 Points
Posted by Atanu Mondal
Atanu Mondal
1,976 Points

if I use protected to the property and then override why is not compiling ?

I am able to override the property with a public modifier but why is it not compiling with protected as repeatDetector is child class. as per Microsoft doc, it should work, right?

"A protected member is accessible within its class and by derived-class instances."

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

        public override bool Scan(int[] 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
{
    class SequenceDetector
    {
        protected virtual string Description => "";

        public virtual bool Scan(int[] sequence)
        {
            return true;
        }
    }
}

1 Answer

Steven Parker
Steven Parker
231,269 Points
Steven Parker
Steven Parker
231,269 Points

You should've gotten this message: "Bummer: Is the getter of the 'RepeatDetector.Description' property public?"

That's the challenge hinting that you need to make the property public instead of protected. You're right about the access of a protected property, but this one needs to be accessible by code (which is not shown here) that is outside of the class and its base.

The need for public access is implied by what the property contains, as a description of what the object is for would obviously not be used within the object itself.