This document describes the NSKeyValueCoding informal protocol, which defines a mechanism allowing applications to access the properties of an object indirectly by name (or key), rather than directly through invocation of an accessor method or as instance variables.

You should read this document to gain an understanding of how to use key-value coding in your applications and how to make your classes key-value coding compliant for interacting with other technologies. Key-value coding is a fundamental technology when working with key-value observing, Cocoa bindings, Core Data, and making your application AppleScript-able. You are expected to be familiar with the basics of Cocoa development and the Objective-C language.

Organization of This Document

Key-Value Coding includes these articles:

See Also

There are other technologies, not covered in this document, that are related to key-value coding.