Instance Method


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



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.


Options for the search—you can combine any of the following using a C bitwise OR operator: NSCaseInsensitiveSearch, NSLiteralSearch, NSNumericSearch.

See String Programming Guide for details on these options.


The range of the receiver over which to perform the comparison. The range must not exceed the bounds of the receiver.


An instance of NSLocale. To use the current locale, pass [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 value that indicates the lexical ordering of a specified range within the receiver and a given string. orderedAscending if the substring of the receiver given by range precedes aString in lexical ordering for the locale given in dict, orderedSame if the substring of the receiver and aString are equivalent in lexical value, and orderedDescending if the substring of the receiver follows aString.


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”.

See Also

Identifying and Comparing Strings

func caseInsensitiveCompare(String)

Returns the result of invoking compare(_:options:) with NSCaseInsensitiveSearch as the only option.

func localizedCaseInsensitiveCompare(String)

Compares the string with a given string using a case-insensitive, localized, comparison.

func compare(String)

Returns the result of invoking compare(_:options:range:) with no options and the receiver’s full extent as the range.

func localizedCompare(String)

Compares the string and a given string using a localized comparison.

func compare(String, options: NSString.CompareOptions = [])

Compares the string with the specified string using the given options.

func localizedStandardCompare(String)

Compares strings as sorted by the Finder.

func hasPrefix(String)

Returns a Boolean value that indicates whether a given string matches the beginning characters of the receiver.

func hasSuffix(String)

Returns a Boolean value that indicates whether a given string matches the ending characters of the receiver.

func isEqual(to: String)

Returns a Boolean value that indicates whether a given string is equal to the receiver using a literal Unicode-based comparison.

var hash: Int

An unsigned integer that can be used as a hash table address.

struct NSString.CompareOptions

These values represent the options available to many of the string classes’ search and comparison methods.

struct NSString.EncodingConversionOptions

Options for converting string encodings.