Question

   int? _fileControlNo = null;
   public int? FileControlNo
    {
        get { return _fileControlNo; }
        set { _fileControlNo = value; }
    }

I’m getting a syntax error when I assign null values to the above properties.

objDPRUtils.FileControlNo =sArrElements.Value(3)==null ? null : Convert.ToInt32(sArrElements.Value(3));

Please, can anyone explain to me why the error occurs if I’m able to set null value in valuetype object using Nullable Type.

Answer 1

The results of the conditional operators need to be of the same type or types that can be implicitly convertible to each other.

In your case you have a null and an Int32 – these violate that requirement.

If instead of an Int32 you return a nullable Int32, the null can be implicitly converted to this type and your code will work (or alternatively, cast the null to an int?).