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What the difference is between delegate and KVO?
KVO should be used to observe changes in property for an object. Delegates should be used when there are lots of callbacks and only one object is desired to be notified. Delegates are objects that acts as another program when an event fires.
What is the difference between delegate and notification in Swift?
use delegates when you want the receiving object to influence an action that will happen to the sending object. use notifications when you need to inform multiple objects of an event.
What is delegate in Swift?
A delegate is an object that acts on behalf of, or in coordination with, another object when that object encounters an event in a program. The delegating object is often a responder object–that is, an object inheriting from NSResponder in AppKit or UIResponder in UIKit–that is responding to a user event.
What is KVO and KVC?
The Other way which is better In this kind of scenarios is (also Apple using this in its libraries a lot) known as KVO(Key Value Observing), which is also directly related to another powerful mechanism called KVC(Key Value Coding). Note: Any property we want to observe for changes must be KeyValueCoding (KVC)complaint.
What is KVO in Objective C?
Key-Value-Observing (KVO) allows you to observe changes to a property or value. To observe a property using KVO you would identify to property with a string; i.e., using KVC. Therefore, the observable object must be KVC compliant.
What is the difference between delegate and datasource?
A data source is like a delegate except that, instead of being delegated control of the user interface, it is delegated control of data. A data source is an outlet held by NSView and UIView objects such as table views and outline views that require a source from which to populate their rows of visible data.
What is delegate in Objective-C?
An Objective-C delegate is an object that has been assigned to the delegate property another object. To create one, you define a class that implements the delegate methods you’re interested in, and mark that class as implementing the delegate protocol.
Why do we use delegate in Swift?
Delegation is used for everything from handling table view events using UITableViewDelegate , to modifying cache behavior using NSCacheDelegate . The core purpose of the delegate pattern is to allow an object to communicate back to its owner in a decoupled way.
What is KVO and KVC in Swift?
KVO and KVC or Key-Value Observing and Key-Value Coding are mechanisms originally built and provided by Objective-C that allows us to locate and interact with the underlying properties of a class that inherits NSObject at runtime.
What is KVC in IOS Swift?
According to Apple: Key-value coding is a mechanism for accessing an object’s properties indirectly, using strings to identify properties, rather than through invocation of an accessor method or accessing them directly through instance variables.
What is atomic and Nonatomic in Swift?
Atomic means only one thread accesses the variable (static type). Atomic is thread-safe, but it is slow. Nonatomic means multiple threads access the variable (dynamic type). Nonatomic is thread-unsafe, but it is fast.