Nested foreach refactoring

Question

I have this piece of code:

  foreach (var customer in customers)
  {
    foreach (var notifier in this.notifiers)
    {
      notifyCustomer(notifier, customer);
    }
  }

Is it possible to do the same action using one foreach or Linq, or even in a more elegant way?

Answer 1

There are various things you could do, such as:

foreach ((notifier, customer) in customers.SelectMany(c => this.notifiers.Select(n => (n, c)))
{
    notifyCustomer(notifier, customer);
}

... But I think you'll agree it's worse than what you have!

What you have makes it clear that you're calling notifyCustomer for each combination of notifier and customer, and I don't think there's a way of improving that.