- What are property wrappers in Swift?
- How do I download asynchronous images in Swift?
- What is KeyPath in Swift?
- What is type property in Swift?
- What is newValue in Swift?
- What is a static variable in Swift?
- Will set did set Swift?
- Why we use lazy VAR in Swift?
- How many protocols can a swift class adopt?
- What is didSet in Swift?
- What are closures in Swift?
- What is lazy loading in iOS Swift?
- How do I cache an image in Swift?
- What is optional in Swift?
- What is class VAR in Swift?
What are property wrappers in Swift?
What is a property wrapper in Swift.
A property wrapper is a generic structure that encapsulates read and write access to the property and adds additional behavior to it..
How do I download asynchronous images in Swift?
Architecting Asynchronous Image Download and Caching in SwiftGiven the image URL, download the image from that URL.Download should happen in the background, and thus should not block the main thread.It may simultaneously be used by different parts of app.It should be thread safe.Should be configurable from outside.It should cache images.Apr 26, 2020
What is KeyPath in Swift?
What’s a KeyPath in Swift? Keypaths in Swift are a way of storing a reference to a property, as opposed to referencing property’s value itself. It’s like working with the name of the property, and not its value.
What is type property in Swift?
Swift Type Properties Type Properties are used on the type(class/struct/enum) instead of the instance of that type. Type Properties are defined with the keyword static . Static Type Properties can’t be overridden in the subclass. … class keyword isn’t supported with stored properties.
What is newValue in Swift?
Swift lets you add code to be run when a property is about to be changed or has been changed. … In willSet Swift provides your code with a special value called newValue that contains what the new property value is going to be, and in didSet you are given oldValue to represent the previous value.
What is a static variable in Swift?
Static variables are those variables whose values are shared among all the instance or object of a class. When we define any variable as static, it gets attached to a class rather than an object. … You create static variable by appending static keyword in front of your variable declaration.
Will set did set Swift?
It will only get called whenever you set the property by assigning a new value to it. It will always get called even if you assign the same value to it multiple times. willSet and didSet both have a default parameters newValue and oldValue. … These parameters are constants, hence you cannot mutate their values.
Why we use lazy VAR in Swift?
Swift has a mechanism built right into the language that enables just-in-time calculation of expensive work, and it is called a lazy variable. These variables are created using a function you specify only when that variable is first requested. … The lazy property is marked as lazy var .
How many protocols can a swift class adopt?
Since classes, structures and, enums can conform to more than one protocol, they can take the default implementation of multiple protocols. This is conceptually similar to multiple inheritance in other languages.
What is didSet in Swift?
Swift’s solution is property observers, which let you execute code whenever a property has changed. To make them work, we use either didSet to execute code when a property has just been set, or willSet to execute code before a property has been set.
What are closures in Swift?
Closures are self-contained blocks of functionality that can be passed around and used in your code. Closures in Swift are similar to blocks in C and Objective-C and to lambdas in other programming languages. … Nested functions are closures that have a name and can capture values from their enclosing function.
What is lazy loading in iOS Swift?
Lazy initialization (also sometimes called lazy instantiation, or lazy loading) is a technique for delaying the creation of an object or some other expensive process until it’s needed. When programming for iOS, this is helpful to make sure you utilize only the memory you need when you need it.
How do I cache an image in Swift?
Cache Images in a UICollectionView Using NSCache in Swift 5Understanding what an NSCache is and how to use it.Creating a centered UICollectionView layout.Executing image-loading tasks on a background thread.Understanding why it is better to use an NSCache instead of a plain Dictionary when we want to cache heavy objects.Sep 10, 2020
What is optional in Swift?
An optional in Swift is basically a constant or variable that can hold a value OR no value. The value can or cannot be nil. It is denoted by appending a “?” after the type declaration. … This is a big impact on the language Swift itself because what that means is that anything non-optional types can never be nil.
What is class VAR in Swift?
A class variable is like a static variable in that you access it by calling MyClass. myVar however static variables can’t be overwritten in subclasses, while class variables can be. https://stackoverflow.com/questions/25731156/swift-what-class-var-means/56469706#56469706. Share. Share a link to this answer.