How does SwiftUI state’s work ?

In SwiftUI, state management is a fundamental concept that allows views to react to changes in data. Here's how it works:

1. State: SwiftUI uses the @State property wrapper to create an internal source of data for a view. When you mark a view property with @State, SwiftUI manages the storage and provides it back for the view to read and write. This allows the view to update automatically when the state changes. For example, if you have a view that displays a rating, you can use state to keep track of the current rating and update it over time. SwiftUI will automatically update the UI when the state changes.

2. Binding: A binding creates a two-way reference to the state of another view. This is useful when you want to share state between different views. For instance, if you have a container view that includes a rating view and a gauge, you can use a binding to ensure that both views are synchronized with the same state.

3. Data-Driven Updates: SwiftUI maintains a representation of the user interface behind the scenes. As data changes, new view values are created and given to SwiftUI, which uses these values to determine how to update its outputs. This eliminates the need for boilerplate code and reduces the likelihood of update bugs.

4. Declarative Syntax: SwiftUI views are expressed declaratively, meaning you describe what you want the UI to look like, and SwiftUI takes care of the rest. This approach allows for a more intuitive and less error-prone way of building user interfaces.

For more detailed information, you can refer to the session SwiftUI essentials (08:50) which covers the fundamentals of views and state management in SwiftUI.