What does this mean in C# or LINQ? - ( () => )

Question

I was going through Jeffrey Palermo's book and came across this syntax.

private void InitializeRepositories()
{
    Func<IVisitorRepository> builder =  () => new VisitorRepository();
    VisitorRepositoryFactory.RepositoryBuilder = builder;
}

What does it mean?

Answer 1

() => indicates a lambda expression that takes no arguments.