# rangeOfCharacter(from:options:range:) Finds and returns the range in the string of the first character from a given character set found in a given range with given options. ``` func rangeOfCharacter(from searchSet: CharacterSet, options mask: NSString.CompareOptions = [], range rangeOfReceiverToSearch: NSRange) -> NSRange ``` ## Parameters `searchSet` A character set. This value must not be `nil`. Raises an `NSInvalidArgumentException` if `aSet` is `nil` . `mask` A mask specifying search options. The following options may be specified by combining them with the C bitwise `OR` operator: [`anchored`](/documentation/Foundation/NSString/CompareOptions/anchored), [`backwards`](/documentation/Foundation/NSString/CompareOptions/backwards). `rangeOfReceiverToSearch` The range in which to search. `aRange` must not exceed the bounds of the receiver. Raises an [`rangeException`](/documentation/Foundation/NSExceptionName/rangeException) if `aRange` is invalid. ## Return Value The range in the receiver of the first character found from `aSet` within `aRange`. Returns a range of `{``NSNotFound``, 0}` if none of the characters in `aSet` are found. ## Discussion This method does not perform any Unicode normalization on the receiver, so canonically equivalent forms will not be matched. For example, searching the string “strüdel”—containing the decomposed characters “`u`” (`U+0075 LATIN SMALL LETTER U`) and “`¨`” (`U+0308 COMBINING DIAERESIS`)—with a character set containing the precomposed character “`ü`” (`U+00FC LATIN SMALL LETTER U WITH DIAERESIS`) would return the range `{``NSNotFound``, 0}`, because none of the characters in the set are found. --- 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)