swift

Combine operators transform, filter, and combine publisher streams. I chain operators to build complex async pipelines declaratively. map transforms values, filter removes unwanted elements, removeDuplicates prevents redundant updates. debounce delays

SwiftUI revolutionizes iOS development with declarative syntax where you describe what the UI should look like based on state. Views automatically update when state changes using property wrappers like @State, @Binding, and @ObservedObject. The @State

View modifiers encapsulate reusable styling and behavior in SwiftUI. Creating custom modifiers keeps views clean and promotes consistency. I define modifiers by conforming to the ViewModifier protocol, implementing body(content:) that transforms the c

Grand Central Dispatch (GCD) manages concurrent code execution with dispatch queues. The main queue handles UI updates—I use DispatchQueue.main.async to return to main thread after background work. Global queues provide concurrent background execution

SwiftUI's NavigationStack introduced in iOS 16 provides programmatic navigation with type-safe paths. I use NavigationPath to manage navigation state, enabling deep linking and state restoration. The navigationDestination modifier maps path values to

WKWebView displays web content with modern WebKit rendering engine. It replaces deprecated UIWebView with better performance and security. I configure WKWebViewConfiguration to customize behavior like JavaScript, cookies, and media playback. Navigatio

Dark mode provides low-light interface that reduces eye strain and saves battery on OLED displays. iOS automatically switches based on system settings or user preference. I use semantic colors like .label, .secondaryLabel, and .systemBackground that a

SwiftUI's .task modifier handles async operations tied to view lifecycle. The task starts when the view appears and cancels automatically when it disappears, preventing memory leaks. I use .task for data fetching, subscriptions, and long-running opera

App extensions expand app functionality into other parts of iOS. Today widgets display glanceable information using WidgetKit with SwiftUI views and timeline providers. Share extensions let users share content to your app from other apps—I process sha

Loading images from URLs requires caching to avoid redundant network calls and improve performance. I create an image cache using NSCache which automatically evicts objects under memory pressure. The cache stores UIImage or Data keyed by URL. For asyn

CloudKit syncs app data across a user's devices via iCloud. Public databases share data with all users, private databases store user-specific data, and shared databases enable collaboration. I define record types with fields in the CloudKit Dashboard,

Auto Layout creates flexible UIs that adapt to different screen sizes and orientations. I define constraints programmatically using NSLayoutConstraint or anchors. The anchor API is more readable—view.topAnchor.constraint(equalTo: parent.topAnchor). Se