Key-Value Observing
E427885
Key-Value Observing is an Objective-C and Swift mechanism that lets objects be notified and react when specific properties of other objects change.
All labels observed (1)
| Label | Occurrences |
|---|---|
| Key-Value Observing canonical | 1 |
How this entity was disambiguated
This entity first appeared as the object of triple T4275594 — resolving that mention is where its identity was fixed. The disambiguator weighed these candidate entities and picked the highlighted one (or “None”, minting a new entity). This is how homonymy is resolved: the same surface form can point to different entities.
Target entity: Key-Value Observing Context triple: [Combine, integratesWith, Key-Value Observing]
-
A.
NSObject
NSObject is the root base class in Objective-C from which most classes in Cocoa and Cocoa Touch inherit, providing fundamental object behavior such as memory management and message sending.
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B.
Objective-C
Objective-C is an object-oriented programming language primarily known for its use in developing software for Apple's macOS and iOS platforms.
-
C.
Core Animation
Core Animation is Apple’s high-performance graphics rendering and animation framework used to create smooth, hardware-accelerated visual effects in macOS, iOS, and other Apple platforms.
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D.
Grand Central Dispatch
Grand Central Dispatch is Apple's low-level concurrency and task scheduling framework used to efficiently manage parallel execution of code on macOS, iOS, and other Darwin-based systems.
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E.
Objective-C runtime
Objective-C runtime is the dynamic library and infrastructure that enables Objective-C’s message passing, dynamic typing, and introspection features at program execution time.
- F. None of above. chosen
- G. Unsure - the case is ambiguous/there is not enough information to decide.
Target entity: Key-Value Observing Target entity description: Key-Value Observing is an Objective-C and Swift mechanism that lets objects be notified and react when specific properties of other objects change.
-
A.
NSObject
NSObject is the root base class in Objective-C from which most classes in Cocoa and Cocoa Touch inherit, providing fundamental object behavior such as memory management and message sending.
-
B.
Objective-C
Objective-C is an object-oriented programming language primarily known for its use in developing software for Apple's macOS and iOS platforms.
-
C.
Core Animation
Core Animation is Apple’s high-performance graphics rendering and animation framework used to create smooth, hardware-accelerated visual effects in macOS, iOS, and other Apple platforms.
-
D.
Grand Central Dispatch
Grand Central Dispatch is Apple's low-level concurrency and task scheduling framework used to efficiently manage parallel execution of code on macOS, iOS, and other Darwin-based systems.
-
E.
Objective-C runtime
Objective-C runtime is the dynamic library and infrastructure that enables Objective-C’s message passing, dynamic typing, and introspection features at program execution time.
- F. None of above. chosen
Statements (48)
| Predicate | Object |
|---|---|
| instanceOf |
Objective-C feature
ⓘ
Swift feature ⓘ observer pattern implementation ⓘ |
| alsoKnownAs | KVO NERFINISHED ⓘ |
| AppleDocumentationTopic | Key-Value Observing Programming Guide NERFINISHED ⓘ |
| basedOn | Key-Value Coding NERFINISHED ⓘ |
| canObserve |
Objective-C properties
ⓘ
Swift properties exposed to Objective-C ⓘ |
| changeType |
NSKeyValueChange.insertion
ⓘ
NSKeyValueChange.removal ⓘ NSKeyValueChange.replacement ⓘ NSKeyValueChange.setting ⓘ |
| collectionProxyClass |
NSKeyValueArray
NERFINISHED
ⓘ
NSKeyValueOrderedSet NERFINISHED ⓘ NSKeyValueSet NERFINISHED ⓘ |
| commonIssue |
crashes from dangling observers
ⓘ
over-observation of frequently changing properties ⓘ |
| coreConcept |
change dictionary
ⓘ
key path ⓘ observation context ⓘ observed object ⓘ observer object ⓘ |
| definedInFramework | Foundation framework NERFINISHED ⓘ |
| improvedIn | Swift block-based API ⓘ |
| introducedIn | Cocoa NERFINISHED ⓘ |
| notificationMethod | observeValueForKeyPath:ofObject:change:context: ⓘ |
| platform |
iOS
ⓘ
macOS ⓘ tvOS NERFINISHED ⓘ watchOS NERFINISHED ⓘ |
| primaryPurpose |
notify observers of value changes
ⓘ
observe property changes ⓘ |
| relatedConcept |
Combine framework
NERFINISHED
ⓘ
NotificationCenter NERFINISHED ⓘ delegation pattern ⓘ |
| requires | KVC-compliant properties ⓘ |
| requiresCareWith | observer lifetime management ⓘ |
| supportsCollectionObserving | to-many relationships ⓘ |
| supportsFeature |
automatic notifications for property changes
ⓘ
manual notifications for property changes ⓘ |
| SwiftAPI |
KeyPath-based observing
ⓘ
NSKeyValueObservation NERFINISHED ⓘ |
| typicalUseCase |
data binding
ⓘ
model-view synchronization ⓘ reactive UI updates ⓘ |
| usedInLanguage |
Objective-C
NERFINISHED
ⓘ
Swift NERFINISHED ⓘ |
| usesMechanism | Objective-C runtime ⓘ |
How these facts were elicited
The pipeline generated the facts above by prompting gpt-5.1 with this entity's name + description and the instruction below.
You are a knowledge base construction expert. Given a subject entity and a description of it, return factual statements that you know for the subject as a JSON list of dictionaries(triples), where keys must be "subject", "predicate" and "object". The number of facts may be very high, between 25 to 50 or more, for very popular subjects. For less popular subjects, the number of facts can be very low, like 5 or 10. # Requirements - If you don't know the subject at all, return an empty list. - If the subject is not a named entity, return an empty list. - Include at least one triple where predicate is "instanceOf". - Do not get too wordy. - Separate several objects into multiple triples with one object.
Subject: Key-Value Observing Description of subject: Key-Value Observing is an Objective-C and Swift mechanism that lets objects be notified and react when specific properties of other objects change.
Referenced by (1)
Full triples — surface form annotated when it differs from this entity's canonical label.