Question

I am trying to create a Collection with properties and their respective accessors.

Here is my code:

class SongCollection : List<Song>
{
    private string playedCount;
    private int totalLength;

    public string PlayedCount
    {
        get
        {
            foreach (Song s in this)
            {
                if (s.TimesPlayed > 0)
                {
                    return s.ToString();
                }
            }
        }
    }


    public int TotalLength
    {
        get
        {
            foreach (Song s in this)
            {
                int total = 0;
                total += s.LengthInSeconds;
            }
            return total;
        }
    }
}

I’m receiving the error at the “get” point. It tells me that not all code paths return a value… What exactly does this mean, and what am I missing?

Answer 1

Firstly, the reason you’re getting that message is that if this is empty, then the code within the foreach block (which is where the required return statement is) would never be executed.

However, your TotalLength() function would always return the length of the first Song, as you’re declaring your variable, setting its value, then returning it within the foreach block. Instead, you’d need to do something like this:

int totalLength = 0;

foreach(Song s in this)
{
    total += s.LengthInSeconds;
}

return totalLength;

Your PlayedCount function suffers from similar issues (if the collection is empty or contains no elements whose TimesPlayed property is greater than 0, then there would be no way for it to return a value), so judging by your comment you could write it this way:

public int PlayedCount()
{
    int total = 0;

    foreach(Song s in this)
    {
        if (s.TimesPlayed > 0)
        {
            total++;
        }
    }

    return total;
}