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C# Intermediate C# Polymorphism Virtual Methods

Posted by Victor Gavojdea
Victor Gavojdea
11,796 Points

Intermediate C# - Virtual Methods: "not all code paths return a value" Not sure what the problem is...

When I add a return false into the code - usually in an else or outside the if statement - I get an "unreachable code detected" warning.

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 previousValue;
            for(int i = 0; i < sequence.Length; i++)
            {
                if(i == 0)
                {
                    previousValue = sequence[i];
                }
                else
                {
                    previousValue = sequence[i--];
                }

                if(sequence[i] == previousValue)
                {
                    return true;
                }
            }
        }
    }
}

2 Answers

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

If your test always fails, your method will not return anything.

To avoid this error, add a "return false;" after the loop, and right before the closing brace of the method.

You might need to revise your logic a bit also, but this will at least get you past the compile issue.

Victor Gavojdea
Victor Gavojdea
11,796 Points

Thank you!

Mohamed Monir
Mohamed Monir
22,362 Points
Mohamed Monir
Mohamed Monir
22,362 Points

namespace Treehouse.CodeChallenges { class RepeatDetector : SequenceDetector { public override bool Scan(int[] sequence) { for(int i =0 ; i < sequence.Length -1 ; i++) {
if(sequence[i]==sequence[i+1]) {
return true; } } return false; } } }