Posts

Showing posts from January, 2022

What is @State in SwiftUI ?

The  @State  keyword is a  @propertyWrapper , a feature just recently introduced in Swift 5.1   State is a value or a set of values, that can change over time, and that affects a view’s behaviour, content, or layout. You use property with the @State attribute to add a state to a view. when you initialize a property that's marked  @State , you're not actually creating your own variable, but rather prompting  SwiftUI  to create  "something"  in the background that stores what you set and monitors it from now on! Your  @State var  just acts as a  delegate to access this wrapper . Every time your  @State  variable is  written ,  SwiftUI  will know as it is monitoring it. It will also know whether the  @State  variable was  read  from the  View 's  body . Using this information, it will be able to  recompute any  View  having referenced a  @State  variable in its  body  after a change to this variable. Code Example:- import SwiftUI struct ContentView : View