Question

I have a method foo(params[] items)

I have a collection (List, Set, …)
I want to send its items to foo as items

what syntax can I use?

Answer 1

If you pass array as only param it will be passed as items. So just use Collection.ToArray. Actually there is something good to know about when you’re using params. If you pass null with intention to pass it as first and only param it will be used as null array. So with code like this:

SomeMethod(null);

public void SomeMethod(params object[] items)
{
...
}

Items will be null, not array with length of 1 and null as first elem.