Question

a simple question:

Is there a syntax for this kind of operation in C#:

• If condition, return the object itself : default value

Like in below example, but I don’t want to evaluate the myObject twice (which could be some much more complicated thing like database query):

int myVar = (myObject == DBNull.Value ? 0 : (int)myObject);

I know there is syntax for this when checking null (like in below example), but is there for checking any different value, like DBNull.Value in this case?

int myVar = Convert.ToInt32(myObject ?? 0);

Answer 1

No:

int myVar = myObject == DBNull.Value ? 0 : (int)myObject;

Is the best you can do. It doesn’t evalutate the object twice just because it is mentioned twice.

Or wrap it in a function of course:

int myVar = DBObjectToInt(myObject);

public static int DBObjectToInt(object dbObj)
{
  return dbObj == DBNull.Value ? 0 : (int)dbObj;
}

Another option is using Coalesce in your SQL, so you don’t even get a DBNull in the first place.