# enumerateRanges(in:options:using:) Enumerates over the ranges in the range of objects using the block ``` func enumerateRanges(in range: NSRange, options opts: NSEnumerationOptions = [], using block: (NSRange, UnsafeMutablePointer) -> Void) ``` ## Parameters `range` The range of items to enumerate. If the range intersects a range of the receiver’s indexes, then that intersection will be passed to the block. `opts` A bitmask that specifies the [`NSEnumerationOptions`](/documentation/Foundation/NSEnumerationOptions) for the enumeration. `block` The block to apply to elements in the index set. The block takes two arguments: - range: The range of elements. - stop: A reference to a Boolean value. The block can set the value to to stop further processing of the array. The stop argument is an out-only argument. You should only ever set this Boolean to within the Block. ## Discussion By default, the enumeration starts with the first object and continues serially through the indexed set range to the last object in the range. You can specify `NSEnumerationConcurrent` and/or `NSEnumerationReverse` as enumeration options to modify this behavior. This method executes synchronously. > Important: > If the Block parameter is `nil` this method will raise an exception. --- 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)