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C# Intermediate C# Polymorphism Virtual Methods

Koray Erkan
Koray Erkan
1,235 Points
Posted by Koray Erkan
Koray Erkan
1,235 Points

Why this code doesn't work? I couldn't handle it.

It gives error when I try to compile the code. I tried adding an else statement to return false but it didn't work either. Can you see where is the mistake? Thank you inadvance.

SequenceDetector.cs 
namespace Treehouse.CodeChallenges
{
    class SequenceDetector
    {
        public virtual bool Scan(int[] sequence)
        {
            return true;
        }
    }
}
RepeatDetector.cs 
namespace Treehouse.CodeChallenges
{
    class RepeatDetector : SequenceDetector
    {
        public override bool Scan (int[] sequence)
        {
            for (int i = 0; i <= (sequence.Length); i++)
            {
                if (sequence[i+1] == sequence[i])
                {
                    return true;
                }
            }
            return false;
        }
    }
}
Christian Andersson
Christian Andersson
8,712 Points

you probably want sequence.length in lowercase.

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

:x: Lowercase "length" is not an array property.

1 Answer

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

:point_right: Your loop is running more times than you have elements.

For a normal iteration of all elements, you would stop before you reach the length ("<" instead of "<="). But in this case, since you're adding to the index in your comparison, you need to stop at one less than that.

Koray Erkan
Koray Erkan
1,235 Points
Koray Erkan
Koray Erkan
1,235 Points

Thank you Steven. It worked when I said "i < (sequence.Length - 1)"