JSON-Data be loaded, but seems that it can't decoded-CodePudding

I have the following code do decode a JSON-String:

        guard let newTutorial = try? JSONDecoder().decode(TutorialModel.self, from: data) else { return }
        DispatchQueue.main.async { [weak self] in
            self?.tutorials.append(newTutorial)
        }

In the console the string would be viewed like this:

Successfully Downloaded Data
Optional("[\n    {\n        \"id\": 1,\n        \"headline\": \"How to messure the T8\",\n        \"descriptiontext\": \"Learn how to messure the T8\"\n    },\n    {\n        \"id\": 2,\n        \"headline\": \"How to messure the Tiger 5000s\",\n        \"descriptiontext\": \"Learn how to messure the Tiger 5000s\"\n    }\n]")

The original String, that be from the server is:

[
{
    "id": 1,
    "headline": "How to messure the T8",
    "descriptiontext": "Learn how to messure the T8"
},
{
    "id": 2,
    "headline": "How to messure the Tiger 5000s",
    "descriptiontext": "Learn how to messure the Tiger 5000s"
}
]

And when I like to view the data, then there is no data in the array:

    List {
        ForEach (vm.tutorials) { tutorial in
            VStack {
                Text(tutorial.headline)
                    .font(.headline)
                Text(tutorial.descriptiontext)
                    .foregroundColor(.gray)
            }
        }
    }

Could it be, that this JSON-String is not correct?

The struct is:

struct TutorialModel: Identifiable, Codable {
    let id: Int
    let headline, descriptiontext: String
}

CodePudding user response：

your json data seems to be correct. It is an array of TutorialModel, not one TutorialModel, so decode the response as an array such as:

guard let newTutorial = try? JSONDecoder().decode([TutorialModel].self, from: data) else { return }
 DispatchQueue.main.async { [weak self] in
     self?.tutorials = newTutorial
 }