# formSymmetricDifference(_:) Removes the elements of the set that are also in the given sequence and adds the members of the sequence that are not already in the set. ``` mutating func formSymmetricDifference(_ other: Set) ``` ## Parameters `other` Another set. ## Discussion In the following example, the elements of the `employees` set that are also members of `neighbors` are removed from `employees`, while the elements of `neighbors` that are not members of `employees` are added to `employees`. In particular, the names `"Alicia"`, `"Chris"`, and `"Diana"` are removed from `employees` while the names `"Forlani"` and `"Greta"` are added. ``` var employees: Set = ["Alicia", "Bethany", "Chris", "Diana", "Eric"] let neighbors: Set = ["Bethany", "Eric", "Forlani", "Greta"] employees.formSymmetricDifference(neighbors) print(employees) // Prints "["Diana", "Chris", "Forlani", "Alicia", "Greta"]" ``` --- 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)