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C# Intermediate C# Polymorphism Virtual Methods

Posted by chanjong kim
chanjong kim
2,315 Points

I have no idea why it keeps showing error

HI, I am working on overriding the Scan method in RepeatDetector.cs that should return 'true' when a value in array is the same with immediately preceding it.

in for loop, if(sequence[i]==sequence[i-1]) { return true; break; }

is what I wrote and i think it makes sense. could you help me to find why it throws compiler error?

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

}

1 Answer

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

If no repeat is found, the method ends without returning anything. But it is declared as returning a bool. So you'll need a "return false;" after the loop ends.

Also, you don't need the "break" since nothing after a "return" will ever be executed.