# subscript(_:) Accesses a contiguous subrange of the collection’s elements. ``` subscript(bounds: Range.Index>) -> AnyCollection.SubSequence { get } ``` ## Parameters `bounds` A range of the collection’s indices. The bounds of the range must be valid indices of the collection. ## Overview For example, using a `PartialRangeFrom` range expression with an array accesses the subrange from the start of the range expression until the end of the array. ``` let streets = ["Adams", "Bryant", "Channing", "Douglas", "Evarts"] let streetsSlice = streets[2..<5] print(streetsSlice) // ["Channing", "Douglas", "Evarts"] ``` The accessed slice uses the same indices for the same elements as the original collection. This example searches `streetsSlice` for one of the strings in the slice, and then uses that index in the original array. ``` let index = streetsSlice.firstIndex(of: "Evarts")! // 4 print(streets[index]) // "Evarts" ``` Always use the slice’s `startIndex` property instead of assuming that its indices start at a particular value. Attempting to access an element by using an index outside the bounds of the slice may result in a runtime error, even if that index is valid for the original collection. ``` print(streetsSlice.startIndex) // 2 print(streetsSlice[2]) // "Channing" print(streetsSlice[0]) // error: Index out of bounds ``` > Complexity: O(1) --- 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)