# init(for:) Returns the class description for a given class. ``` init?(for aClass: AnyClass) ``` ## Parameters `aClass` The class for which to return a class description. See note below for important details. ## Return Value The class description for `aClass`, or `nil` if a class description cannot be found. ## Discussion If a class description for `aClass` is not found, the method posts an NSClassDescriptionNeededForClassNotification on behalf of `aClass`, allowing an observer to register a class description. The method then checks for a class description again. Returns `nil` if a class description is still not found. If you have an instance of the receiver’s class, you can use the `NSObject` instance method instead. > Note: > In macOS 10.6 and later, this method (and as a result methods of any object) will return `nil` when the sdef contains no `` element for the Cocoa class, but there is a `` element defined for a superclass. > > This is incorrect, as object instances should never be required to be exactly a given class, any class should be allowed to be a subclass of the required class and receive the correct `` value. > > This situation can have a serious impact on Cocoa Scripting, and there is no plan on changing this behavior. > > Instead of using this method, you should use the ``doc://com.apple.foundation/documentation/Foundation/NSScriptClassDescription/init(for:)`` method of ``doc://com.apple.foundation/documentation/Foundation/NSScriptClassDescription`` instead. ## See Also [Cocoa Scripting Guide](https://developer.apple.com/library/archive/documentation/Cocoa/Conceptual/ScriptableCocoaApplications/SApps_intro/SAppsIntro.html#//apple_ref/doc/uid/TP40002164) [Key-Value Coding Programming Guide](https://developer.apple.com/library/archive/documentation/Cocoa/Conceptual/KeyValueCoding/index.html#//apple_ref/doc/uid/10000107i) --- 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)