Question

I have seen how to initialize var to null. This does not help in my situation. I have

string nuller = null;
var firstModel = nuller;
if(contextSelectResult.Count() > 0)
    firstModel = contextSelectResult.First();

I get error

Cannot implicitly convert type
‘SomeNamespace.Model.tableName’ to ‘string’.

I am trying to avoid try/catching InvalidOperation for First() when no first exists as its expensive. So, how can I get past the scope issue here?

Answer 1

Simply use FirstOrDefault() instead. The whole point of FirstOrDefault is to return the first element of the sequence if it exists, or the default value of the element type (i.e. null for all reference types) otherwise.

Note that in other cases where you wish to check for the existence of any elements, using Any() can sometimes be more efficient than Count() > 0 – it depends on the exact context, but IMO it’s a simpler way of expressing what you’re looking for anyway.