# NSWhoseSpecifier A specifier that indicates every object in a collection matching a condition. ``` class NSWhoseSpecifier ``` ## Overview `NSWhoseSpecifier` specifies every object in a collection (or every element in a container) that matches the condition defined by a single Boolean expression or multiple Boolean expressions connected by logical operators. `NSWhoseSpecifier` is unique among object specifiers in that its top-level container is typically not the application object but an evaluated object specifier involved in the tested-for condition. An `NSWhoseSpecifier` object encapsulates a “test” object for defining this condition. A test object is instantiated from a subclass of the abstract [`NSScriptWhoseTest`](/documentation/Foundation/NSScriptWhoseTest) class, whose one declared method is [`isTrue()`](/documentation/Foundation/NSScriptWhoseTest/isTrue()). See “Boolean Expressions and Logical Operations” in [`NSScriptObjectSpecifier`](/documentation/Foundation/NSScriptObjectSpecifier) and the descriptions in NSComparisonMethods and NSScriptingComparisonMethods for more information. The set of elements specified by an `NSWhoseSpecifier` object can be a subset of those that pass the `NSWhoseSpecifier` object’s test. This subset is specified by the various sub-element properties of the `NSWhoseSpecifier` object . Consider as an example the specifier `paragraphs where color of third word is blue`. This would be represented by an `NSWhoseSpecifier` object that uses a test specifier and another object specifier to identify a subset of the objects with the specified property. That is, the specifier’s property is `paragraphs`; the test specifier is an index specifier with property `words` and `index 3`; and the qualifier is a key value qualifier for key `color` and value `[NSColor blueColor]`. The test object specifier (`word at index 3`) is evaluated for each object (paragraph) using that object as the container; the resulting objects (if any) are tested with the qualifier (`color blue`). `NSWhoseSpecifier` is part of Cocoa’s built-in script handling. You don’t normally subclass it. ## Topics ### Initializing a whose specifier [`- initWithContainerClassDescription:containerSpecifier:key:test:`](/documentation/Foundation/NSWhoseSpecifier/init(containerClassDescription:containerSpecifier:key:test:)) Returns an `NSWhoseSpecifier` object initialized with the given attributes. ### Accessing information about a whose specifier [`endSubelementIdentifier`](/documentation/Foundation/NSWhoseSpecifier/endSubelementIdentifier) Sets the end sub-element identifier for the specifier to the value of a given sub-element. [`endSubelementIndex`](/documentation/Foundation/NSWhoseSpecifier/endSubelementIndex) Sets the index position of the last sub-element within the range of objects being tested that pass the specifier’s test. [`startSubelementIdentifier`](/documentation/Foundation/NSWhoseSpecifier/startSubelementIdentifier) Returns the start sub-element identifier for the receiver. [`startSubelementIndex`](/documentation/Foundation/NSWhoseSpecifier/startSubelementIndex) Returns the index position of the first sub-element within the range of objects being tested that pass the receiver’s test. [`test`](/documentation/Foundation/NSWhoseSpecifier/test) Returns the test object encapsulated by the receiver. ### Constants [`SubelementIdentifier`](/documentation/Foundation/NSWhoseSpecifier/SubelementIdentifier) `NSWhoseSpecifier` uses these constants to specify sub-elements within the collection of objects being tested that pass the specifier’s test. ## Relationships ### Inherits From [`NSScriptObjectSpecifier`](/documentation/Foundation/NSScriptObjectSpecifier) ### Conforms To [`CustomStringConvertible`](/documentation/Swift/CustomStringConvertible) [`CVarArg`](/documentation/Swift/CVarArg) [`Hashable`](/documentation/Swift/Hashable) [`NSCoding`](/documentation/Foundation/NSCoding) [`Sendable`](/documentation/Swift/Sendable) [`Equatable`](/documentation/Swift/Equatable) [`SendableMetatype`](/documentation/Swift/SendableMetatype) [`NSObjectProtocol`](/documentation/ObjectiveC/NSObjectProtocol) [`CustomDebugStringConvertible`](/documentation/Swift/CustomDebugStringConvertible) --- 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)