what's the difference between swiftui and uikit

SwiftUI and UIKit are both frameworks used for building user interfaces on Apple platforms, but they have different approaches and features.

SwiftUI

• Declarative Syntax: SwiftUI uses a declarative syntax, meaning you describe what the UI should look like and the framework takes care of the rendering and updates. This allows you to focus on the "what" rather than the "how."
• Cross-Platform: SwiftUI is designed to work across all Apple devices, including iOS, macOS, watchOS, and tvOS. This makes it easier to share code across different platforms.
• Interoperability: SwiftUI can interoperate with UIKit and AppKit. You can use UIViewRepresentable to wrap UIKit views and use them in SwiftUI, and UIHostingController to embed SwiftUI views in UIKit.
• Advanced Features: SwiftUI comes with built-in support for features like dark mode, dynamic type, and accessibility. It also offers a wide range of modifiers and protocols for customization.
• Animations and Gestures: SwiftUI has a robust animation system that can now be used to animate UIKit views as well (Enhance your UI animations and transitions).

UIKit

• Imperative Syntax: UIKit uses an imperative approach, where you explicitly define the steps to create and update the UI. This gives you fine-grained control over the UI elements.
• Rich Capabilities: UIKit has been around for a long time and offers a wide range of capabilities and components that are well-suited for complex and highly customized UIs.
• Interoperability: UIKit can interoperate with SwiftUI, allowing you to incrementally adopt SwiftUI in existing UIKit-based apps. You can use UIHostingController to embed SwiftUI views in UIKit and vice versa.
• Animations and Gestures: UIKit has its own animation and gesture recognition systems, but with iOS 18, you can now use SwiftUI animations to animate UIKit views (What’s new in UIKit).

Summary

• SwiftUI: Best for new projects, cross-platform development, and when you want to write less code with a more modern, declarative syntax.
• UIKit: Best for existing projects, highly customized UIs, and when you need the rich capabilities and fine-grained control it offers.

For more details, you can check out the sessions:

• Platforms State of the Union
• SwiftUI essentials
• What’s new in UIKit