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C# Intermediate C# Polymorphism Virtual Methods

Idan shami
Idan shami
13,251 Points
Posted by Idan shami
Idan shami
13,251 Points

don't understand how to solve the compiler error

RepeatDetector.cs(5,31): error CS0161: `Treehouse.CodeChallenges.RepeatDetector.Scan(int[])': not all code paths return a value Compilation failed: 1 error(s), 0 warnings

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)
         {

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

1 Answer

Chris Adamson
Chris Adamson
132,143 Points
Chris Adamson
Chris Adamson
132,143 Points

The Scan method is required to return a bool. The error means that there exists a possiblity that the method doesn't return anything. In this case, it didn't return false if it didn't find anything.

 namespace Treehouse.CodeChallenges
{
    class RepeatDetector : SequenceDetector
    {
         public override bool Scan(int[] sequence)
         {
           int i = 1;
           int j = i - 1;
           for(;i < sequence.Length;i++)
            {
                if(sequence[i] == sequence[j])
                {
                    return true;
                }
            }
            return false;
         }
    }
}