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

• If both items are null, it considers the two items to be equal.

• If one item is null but the other item is not, it considers the two items to be unequal.

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

• If the first item in the comparison cannot be cast to an IStructuralEquatable object (in other words, if it is not a collection object that implements the IStructuralEquatable interface), it calls the item's Equals method.