# differenceFromArray:withOptions:usingEquivalenceTest: Compares two arrays, using the provided block and with options, to create a difference object that represents the changes between them. ``` - (NSOrderedCollectionDifference *) differenceFromArray:(NSArray *) other withOptions:(NSOrderedCollectionDifferenceCalculationOptions) options usingEquivalenceTest:(BOOL (^)(ObjectType obj1, ObjectType obj2)) block; ``` ## Discussion The options allow you to choose to omit insertion or removal references to the change objects within the difference object’s changes. Don’t use the option [`inferMoves`](/documentation/Foundation/NSOrderedCollectionDifferenceCalculationOptions/inferMoves) when providing a block for the equivalence test. The changes returned in the difference object don’t include valid values for [`associatedIndex`](/documentation/Foundation/NSOrderedCollectionChange/associatedIndex). --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)