# compare(_:options:range:locale:) Compares the string using the specified options and returns the lexical ordering for the range. ``` func compare(_ string: String, options mask: NSString.CompareOptions = [], range rangeOfReceiverToCompare: NSRange, locale: Any?) -> ComparisonResult ``` ## Parameters `string` The string with which to compare the range of the receiver specified by `range`. This value must not be `nil` . If this value is `nil` , the behavior is undefined and may change in future versions of macOS. `mask` Options for the search—you can combine any of the following using a C bitwise OR operator: `NSCaseInsensitiveSearch`, `NSLiteralSearch`, `NSNumericSearch`. See [String Programming Guide](https://developer.apple.com/library/archive/documentation/Cocoa/Conceptual/Strings/introStrings.html#//apple_ref/doc/uid/10000035i) for details on these options. `rangeOfReceiverToCompare` The range of the receiver over which to perform the comparison. The range must not exceed the bounds of the receiver. > Important: > Raises an `NSRangeException` if `range` exceeds the bounds of the receiver. `locale` An instance of [`NSLocale`](/documentation/Foundation/NSLocale). To use the current locale, pass [[`NSLocale`](/documentation/Foundation/NSLocale) [`current`](/documentation/Foundation/NSLocale/current)]. For example, if you are comparing strings to present to the end-user, use the current locale. To use the system locale, pass `nil`. ## Return Value Returns an [`ComparisonResult`](/documentation/Foundation/ComparisonResult) value that indicates the lexical ordering of a specified range within the receiver and a given string. [`ComparisonResult.orderedAscending`](/documentation/Foundation/ComparisonResult/orderedAscending) if the substring of the receiver given by `range` precedes `aString` in lexical ordering for the locale given in `dict`, [`ComparisonResult.orderedSame`](/documentation/Foundation/ComparisonResult/orderedSame) if the substring of the receiver and `aString` are equivalent in lexical value, and [`ComparisonResult.orderedDescending`](/documentation/Foundation/ComparisonResult/orderedDescending) if the substring of the receiver follows `aString`. ## Discussion The `locale` argument affects both equality and ordering algorithms. For example, in some locales, accented characters are ordered immediately after the base; other locales order them after “z”. --- 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)