Control how SwiftUI presents toolbar items and tabs on iPhone Duo with the new iOS 27.1 APIs, from arranging custom labels to prioritizing actions when space is limited.

Learn how to enable SwiftUI's ForEach slow-path diagnostic in Xcode, interpret warnings about variable view counts, and address the reported patterns in List and lazy stacks.

Present grouped data as a multi-level donut chart, where each outer ring reveals a more detailed breakdown and each subgroup aligns with its parent category.

Compare the effects of stored inputs, state, bindings, environment values and observable models on SwiftUI view updates through input comparison, access tracking and subscription behavior.