# Create new Xcode project (use Xcode GUI or swift package init)
mkdir MyApp && cd MyApp
swift package init --type executable --name MyApp

# For iOS/macOS apps, use Xcode:
# File → New → Project → App
# Choose SwiftUI for Interface, Swift for Language

MyApp/
├── MyApp.xcodeproj           # Xcode project
├── MyApp/
│   ├── MyAppApp.swift        # @main App entry point
│   ├── ContentView.swift     # Root view
│   ├── Views/                # SwiftUI views
│   │   ├── HomeView.swift
│   │   └── DetailView.swift
│   ├── Models/               # Data models
│   │   └── Item.swift
│   ├── ViewModels/           # View models (@Observable)
│   │   └── HomeViewModel.swift
│   ├── Services/             # API, persistence, etc.
│   │   └── DataService.swift
│   ├── Resources/
│   │   └── Assets.xcassets
│   └── Info.plist
├── MyAppTests/
└── MyAppUITests/

import SwiftUI

@main
struct MyAppApp: App {
    var body: some Scene {
        WindowGroup {
            ContentView()
        }
    }
}

import SwiftUI

struct CounterView: View {
    @State private var count = 0

    var body: some View {
        VStack {
            Text("Count: \(count)")
                .font(.largeTitle)

            Button("Increment") {
                count += 1
            }
            .buttonStyle(.borderedProminent)
        }
        .padding()
    }
}

import SwiftUI
import Observation

@Observable
class HomeViewModel {
    var items: [Item] = []
    var isLoading = false
    var error: Error?

    func loadItems() async {
        isLoading = true
        defer { isLoading = false }

        do {
            items = try await ItemService.shared.fetchItems()
        } catch {
            self.error = error
        }
    }
}

struct HomeView: View {
    @State private var viewModel = HomeViewModel()

    var body: some View {
        List(viewModel.items) { item in
            Text(item.name)
        }
        .task {
            await viewModel.loadItems()
        }
    }
}

import SwiftUI

struct RootView: View {
    @State private var path = NavigationPath()

    var body: some View {
        NavigationStack(path: $path) {
            List {
                NavigationLink("Go to Detail", value: "detail-id")
            }
            .navigationDestination(for: String.self) { id in
                DetailView(id: id)
            }
            .navigationTitle("Home")
        }
    }
}

func fetchData() async throws -> [Item] {
    let url = URL(string: "https://api.example.com/items")!
    let (data, response) = try await URLSession.shared.data(from: url)

    guard let httpResponse = response as? HTTPURLResponse,
          httpResponse.statusCode == 200 else {
        throw APIError.invalidResponse
    }

    return try JSONDecoder().decode([Item].self, from: data)
}

// Usage in SwiftUI
.task {
    do {
        items = try await fetchData()
    } catch {
        self.error = error
    }
}

import SwiftData

@Model
class Item {
    var name: String
    var createdAt: Date
    var category: Category?

    init(name: String, createdAt: Date = .now) {
        self.name = name
        self.createdAt = createdAt
    }
}

// In App
@main
struct MyAppApp: App {
    var body: some Scene {
        WindowGroup {
            ContentView()
        }
        .modelContainer(for: Item.self)
    }
}

// In View
struct ItemsView: View {
    @Query var items: [Item]
    @Environment(\.modelContext) private var modelContext

    var body: some View {
        List(items) { item in
            Text(item.name)
        }
    }

    func addItem() {
        let item = Item(name: "New Item")
        modelContext.insert(item)
    }
}

# Build from command line
xcodebuild -project MyApp.xcodeproj -scheme MyApp -configuration Debug build

# Run tests
xcodebuild test -project MyApp.xcodeproj -scheme MyApp -destination 'platform=iOS Simulator,name=iPhone 15'

# Archive for distribution
xcodebuild archive -project MyApp.xcodeproj -scheme MyApp -archivePath MyApp.xcarchive

# List available simulators
xcrun simctl list devices

# Boot a simulator
xcrun simctl boot "iPhone 15"

# Install app on simulator
xcrun simctl install booted MyApp.app