> For the complete documentation index, see [llms.txt](https://lochiwei.gitbook.io/ios/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://lochiwei.gitbook.io/ios/appendix/json/load-json.md).

# Load JSON

{% tabs %}
{% tab title="load" %}
:point\_right: SwiftUI Tutorials ⟩ [Building Lists & Navigation](https://developer.apple.com/tutorials/swiftui/building-lists-and-navigation) ⟩ [Create a Landmark Model](https://developer.apple.com/tutorials/swiftui/building-lists-and-navigation#Create-a-Landmark-Model) - Step 9

{% hint style="info" %}
另外的方法請看： [URLSession.DataTaskPublisher](/ios/swift/scope/framework/built-in-frameworks/combine/publishers/urlsession.datataskpublisher.md#jiang-data-zhuan-wei-swift-xing-bie)
{% endhint %}

```swift
import Foundation
import Combine                      // for `ObservableObject`

final class ModelData: ObservableObject {
    // ⭐️ load initial data from JSON
    @Published var landmarks: [Landmark] = load("landmarkData.json")
}

/// ⭐️ fetches JSON data from app’s main bundle.
/// - Returns: an instance of a type conforming to `Decodable`
func load<T: Decodable>(_ filename: String) -> T {
    
    // prepare to get data from file
    let data: Data

    // get file URL from app's main bundle
    // 1. filename -> URL
    guard
        let file = Bundle.main.url(forResource: filename, withExtension: nil)
    else {
        fatalError("Couldn't find \(filename) in main bundle.")
    }

    // 2. URL -> Data
    do {
        data = try Data(contentsOf: file)
    } catch {
        fatalError("Couldn't load \(filename) from main bundle:\n\(error)")
    }

    // 3. Data -> T
    do {
        let decoder = JSONDecoder()
        return try decoder.decode(T.self, from: data)
    } catch {
        fatalError("Couldn't parse \(filename) as \(T.self):\n\(error)")
    }
}

```

{% endtab %}

{% tab title="📘 手冊" %}
\*
{% endtab %}

{% tab title="👥 相關" %}

* [URLSession.DataTaskPublisher](/ios/swift/scope/framework/built-in-frameworks/combine/publishers/urlsession.datataskpublisher.md#jiang-data-zhuan-wei-swift-xing-bie) - URLSession.DataTaskPublisher
  {% endtab %}
  {% endtabs %}