When the IComparer object returned by this property is passed to the comparison method of a collection object, such as Array.System#Collections#IStructuralComparable#CompareTo(object, IComparer) or Tuple`3.System#Collections#IStructuralComparable#CompareTo(object, IComparer), its IComparer.Compare(object, object) method is called for each member of an array or for each component of a tuple. This implementation of the IComparer.Compare(object, object) method behaves as follows when it compares each item of a collection object with the corresponding item of another collection object:

• It considers two items that are null to be equal, and considers a null item to be less than an item that is not null.

• If the first item in the comparison can be cast to an IStructuralComparable object (in other words, if it is a collection object that implements the IStructuralComparable interface), it calls the IStructuralComparable.CompareTo(object, IComparer) method.

• If the first item in the comparison cannot be cast to an IStructuralComparable object (in other words, if it is not a collection object that implements the IStructuralComparable interface), it calls the Comparer.Default.Compare method.