I am getting a 'not all code paths return a value' error in my c# code-CodePudding

I have written a c# extension method that returns any duplicate values in an array of ints and it is telling me that 'not all code paths return a value'. Here is my code:

public static int? FindDuplicate(this int[] arrayToFindDuplicateIn)
    {

        int previousint = int.MaxValue;
        arrayToFindDuplicateIn = arrayToFindDuplicateIn.OrderByDescending(x => x).ToArray();

        foreach (int number in arrayToFindDuplicateIn)
        {
            if (number == previousint)
            {
                return number;
            }
            else
            {
                return null;
            }

            previousint = number;
        }
    }

CodePudding user response：

I think what you want is to remove your else return null; and put the return null; outside your foreach. Otherwise it will only loop once everytime.

CodePudding user response：

If the array is empty, no value is returned, so just return something at the end or check the input array with arrayToFindDuplicateIn.Any()