Is there a better way to express a parameterless lambda than () =>?

Question

The () seems silly. is there a better way?

For example:

ExternalId.IfNotNullDo(() => ExternalId = ExternalId.Trim());

Answer 1

Essentially what you're looking for is the inverse of the ?? null coalescing operator (which is called Nullable.GetValueOrDefault() under the covers) - problem is C# doesn't provide a neat OOTB answer.

Don't know exactly what you're doing but as you are doing:

ExternalId.IfNotNullDo(()=>ExternalId=ExternalId.Trim());

you might also find a use for:

class NullExtensions
{
    public T DefaultOr( this T that, Func transform)
    {
        return that!=default(T) ? transform(that) : default(T);
    }
}

which would enable:

var result = input.DefaultOr( _ => _.Trim());

(in general, I'd be trying to steer away from reusing / mutating variables as you seem to be doing and instead going in an Introduce Explaining Variable / Split Temporary Variable direction i.e., use a new variable rather than value = value.DefaultOr( _ => _.Trim());)