Property in Swift - Computed property | Property Observers (WillSet & DidSet)

   Computed property -  Computed properties are part of a property type in Swift.  Stored properties are the most common which save and return a stored value  Computed properties calculate (rather than store) a value. A computed property provides a getter and an optional setter to indirectly access other properties and values. Computed property in swift is an interesting topic as you can write code inside a property in swift. Computed properties are provided by classes, structures, and enumerations but stored properties are provided only by classes and structures. This computed property swift tutorial has some tips on how to use the computed property in the right way and avoid the common mistakes that swift programming beginners do while computed property. Example :- Computed property A Calculate Simple Intrest struct CalculateLoan {      var amount : Int      var rate : Int      var years : Int      var simpleInterest: Int {          get {              return ( amount * rate
0

Async await in Swift with code examples

Async await

Async await is a new structured concurrency change that arrived in swift 5.5 during WWDC 2021. Concurrency in swift allowing multiple pices of code run at the same time. With the new async methods and await statement, we can define methods performing work asynchronously. Async replaces closure completion callbacks

Async await


Completion callbacks were common in Swift to return from an asynchronous task,

Exp:-

func fetchImages(completion: (Result<[UIImage], Error>) -> Void) {
    // .. perform data request
}

What Is Async

Async stand for asynchronous 

func fetchImages() async throws -> [UIImage] {
 // .. perform data request 
}

This async method throw async which means that it’s performing a failable asynchronous task. 
The method would return a collection of images if everything went well otherwise throws an error if something went wrong.

What is await?

Await is the keyword to be used for calling Async method. You can say Async & Await both are best friends in swift as one will never go without the other. "Await is waiting a callback from his buddy async"  if call a fetchImages() method then 

do {
    let images = try await fetchImages()
    print("Fetched \(images.count) images.")
} catch {
    print("Fetching images failed with error \(error)")
}

Async- await called a structured concurrency, this method are linearly executed without going back.



Comments

Post a Comment