Top SwiftUI Interview Questions for 2023
Here is a set of top SwiftUI interview questions. If you would like to prepare yourself for an interview I suggest you use the following to give you that helping hand!
Basic SwiftUI Concepts
- Describe views in SwiftUI
A view in SwiftUI is a lightweight transient object designed to be thrown away when the source for it is changed.
That is SwiftUI has a data-driven nature and SwiftUI handles updates by recomputing the body of views where necessary in a performant manner. Developers don’t handle view refresh directly rather the system handles this.
SwiftUI views are
struct under the hood and conform to SwiftUI’s
View protocol in order to describe a user viewable element.
Components and Views
- Describe the difference between
A property wrapper used to create a single source of truth for data in your app which mutates over time (and updating a view appropriately).
The wrappedValue in the state is anything (usually a value type). The wrappedValue is stored on the heap, and when it changes invalidates the View and views depending on this value are marked for update. Article
@Binding property wrapper enables a two-way connection between a property which stores data and a view that displays and mutates that data.
The wappedValue is a value (anything) that is bound to something else. It gets/sets the value of the wrappedValue from some other source. When the bound-to value changes, it invalidates the view marking it for update. Article
ObservedObject and published
In order to make a property observable through
@Published to classes outside the containing class, that containing class would need to inherit from
ObservableObject, and the relevant property should be marked as
@Published — which synthesizes an
objectWillChange publisher to announce that the value will change. Article