# App

[SwiftUI](..) ⟩ [app]() ⟩ App (protocol)

{% hint style="success" %}
A [protocol](../../swift/type/category/protocol) that represents the <mark style="color:yellow;">structure</mark> and <mark style="color:yellow;">behavior</mark> of an [app]().
{% endhint %}

```swift
@main
struct MyApp: App {
    var body: some Scene {
        // ⭐️ app definition
        WindowGroup {
            // ⭐️ at least one view is needed inside `WindowGroup`,
            //    which acts as a container for your app's view hierarchy.
            ContentView()
        }
    }
}
```

{% tabs %}
{% tab title="📘 手冊" %}
* [SwiftUI ](https://developer.apple.com/documentation/swiftui) ⟩ [App organization ](https://developer.apple.com/documentation/swiftui/app-organization) ⟩ [App](https://developer.apple.com/documentation/swiftui/app/)
{% endtab %}

{% tab title="Second Tab" %}

{% endtab %}
{% endtabs %}

