# SwiftUI State Management (iOS)

> @State, @Binding, @ObservedObject, @EnvironmentObject, @StateObject, data flow

- 22 interview questions
- Mid-Level
- [Interview Questions: iOS](https://sharpskill.dev/en/technologies/ios/interview-questions.md)

## 1. Which property wrapper to use for managing local state in a SwiftUI view?

**Answer**

@State creates a source of truth for mutable data within a view. SwiftUI automatically manages the lifecycle and redraws when the value changes. This is the fundamental mechanism for local state modifications in a single view.

## 2. What is the purpose of the @Binding property wrapper in SwiftUI?

**Answer**

@Binding creates a bidirectional reference to an existing source of truth. It allows a child view to modify parent data without owning the source itself. This is essential for parent-child communication while maintaining a single source of authority.

## 3. What is the role of @Published in SwiftUI state management?

**Answer**

@Published marks properties of an ObservableObject class as observable. When a @Published property changes, the class notifies all observers, triggering view redraws. It bridges classes with SwiftUI's reactive system.

## 19 more questions available

- How to access a parent's @State property in a child view?
- When to use @AppStorage instead of @State?

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## Other iOS interview topics

- [Swift Basics](https://sharpskill.dev/en/technologies/ios/interview-questions/swift-basics.md): 25 questions, Junior
- [Swift Language Essentials](https://sharpskill.dev/en/technologies/ios/interview-questions/swift-language-essentials.md): 15 questions, Junior
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- [UserDefaults & Keychain](https://sharpskill.dev/en/technologies/ios/interview-questions/userdefaults-keychain.md): 20 questions, Junior
- [Application Lifecycle](https://sharpskill.dev/en/technologies/ios/interview-questions/app-lifecycle.md): 20 questions, Junior
- [Auto Layout & Constraints](https://sharpskill.dev/en/technologies/ios/interview-questions/auto-layout-constraints.md): 24 questions, Mid-Level
- [UITableView & UICollectionView](https://sharpskill.dev/en/technologies/ios/interview-questions/uitableview-uicollectionview.md): 25 questions, Mid-Level
- [SwiftUI Basics](https://sharpskill.dev/en/technologies/ios/interview-questions/swiftui-basics.md): 18 questions, Mid-Level
- [SwiftUI Navigation](https://sharpskill.dev/en/technologies/ios/interview-questions/swiftui-navigation.md): 18 questions, Mid-Level
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- [Codable & JSON Parsing](https://sharpskill.dev/en/technologies/ios/interview-questions/codable-json-parsing.md): 20 questions, Mid-Level
- [Core Data](https://sharpskill.dev/en/technologies/ios/interview-questions/core-data.md): 22 questions, Mid-Level
- [Protocol Oriented Programming](https://sharpskill.dev/en/technologies/ios/interview-questions/protocol-oriented-programming.md): 20 questions, Mid-Level
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- [iOS Design Patterns](https://sharpskill.dev/en/technologies/ios/interview-questions/ios-design-patterns.md): 24 questions, Senior
- [Performance Optimization](https://sharpskill.dev/en/technologies/ios/interview-questions/performance-optimization.md): 22 questions, Senior
- [Security & Encryption](https://sharpskill.dev/en/technologies/ios/interview-questions/security-encryption.md): 20 questions, Senior
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