# tokenField(_:completionsForSubstring:indexOfToken:indexOfSelectedItem:) Allows the delegate to provide an array of appropriate completions for the contents of the receiver. ``` @MainActor optional func tokenField(_ tokenField: NSTokenField, completionsForSubstring substring: String, indexOfToken tokenIndex: Int, indexOfSelectedItem selectedIndex: UnsafeMutablePointer?) -> [Any]? ``` ## Parameters `tokenField` The token field where editing is occurring. `substring` The partial string that is to be completed. `tokenIndex` The index of the token being edited. `selectedIndex` Optionally, you can return by-reference an index into the returned array that specifies which of the completions should be initially selected. If none are to be selected, return by reference `-1`. ## Return Value An array of strings that are possible completions. ## Discussion If the delegate does not implement this method, no completions are provided. --- 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)