FirstOrDefault: Default value other than null

Question

As I understand it, in Linq the method FirstOrDefault() can return a Default value of something other than null. What I haven\'t worked out is wha

Answer 1

I know its been a while but Ill add to this, based on the most popular answer but with a little extension Id like to share the below:

static class ExtensionsThatWillAppearOnIEnumerables
{
    public static T FirstOr(this IEnumerable source, Func predicate, Func alternate)
    {
        var thing = source.FirstOrDefault(predicate);
        if (thing != null)
            return thing;
        return alternate();
    }
}

This allows me to call it inline as such with my own example I was having issues with:

_controlDataResolvers.FirstOr(x => x.AppliesTo(item.Key), () => newDefaultResolver()).GetDataAsync(conn, item.ToList())

So for me I just wanted a default resolver to be used inline, I can do my usual check and then pass in a function so a class isn't instantiated even if unused, its a function to execute when required instead!