# removeDuplicates() Publishes only elements that don’t match the previous element. ``` func removeDuplicates() -> Publishers.RemoveDuplicates ``` ## Return Value A publisher that consumes — rather than publishes — duplicate elements. ## Discussion Use [`removeDuplicates()`](/documentation/Combine/Publisher/removeDuplicates()) to remove repeating elements from an upstream publisher. This operator has a two-element memory: the operator uses the current and previously published elements as the basis for its comparison. In the example below, [`removeDuplicates()`](/documentation/Combine/Publisher/removeDuplicates()) triggers on the doubled, tripled, and quadrupled occurrences of `1`, `3`, and `4` respectively. Because the two-element memory considers only the current element and the previous element, the operator prints the final `0` in the example data since its immediate predecessor is `4`. ``` let numbers = [0, 1, 2, 2, 3, 3, 3, 4, 4, 4, 4, 0] cancellable = numbers.publisher .removeDuplicates() .sink { print("\($0)", terminator: " ") } // Prints: "0 1 2 3 4 0" ``` --- 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)