Operator ' ' cannot be applied to operand of type <int> and null

Question

I have the below method that accepts BuildAppStat object as parameter.
However it can be null sometimes.

So I am calling it like as :

sourceId: bas.BuildAppStatId ?? null

and getting compile error

operator ' ' cannot be applied to operand of type <int> and null.

How can I fix this?

public PageBuildVrsn EditPageBuildVrsn(string caption, string nameInUse, string description, BuildAppStat bas = null, int pageBuildVrsnTypeId = 1)
{
    PageBuildVrsn pbv = Create(pageBuildVrsnTypeId, caption, nameInUse, description);
    pbv.ParentBuildAppStats = new List<BuildAppStat>();
    pbv.ParentBuildAppStats.Add(
        BasFactory.Create(
            DateTimeOffset.Now,
            true,
            sourceId: bas.BuildAppStatId ?? null
        )
    );

    return pbv;
}

Answer 1

You can only use the null-coalescing operator with a first operand which is a nullable type (either a nullable value type, or any reference type). It sounds like bas.BuildAppStatId is just an int, which means you can't use the null-coalescing operator with it.

If you were trying to guard against bas itself being null, you want:

sourceId: bas == null ? (int?) null : bas.BuildAppStatId,