How to serialize JSON string to multidimensional NSDictionary

Question

"[{\"person\":\"person1\",\"data\":{\"age\":\"10\",\"name\":\"John\"}},
{\"person\":\"person2\",\"data\":{\"age\":\"20\",\"name\":\"Jonathan\"}},
{\"person\":\"person3\",\"data\":{\"age\":\"30\",\"name\":\"Joe\"}}]"

Note that the value "data" is also a dictionary.

I have a JSON string like above and am trying to serialize like:

if let dataFromString = conf.data(using: .utf8, allowLossyConversion: false) {
        let json = try JSON(data: dataFromString)
        
        configuration = json.dictionary ?? [:]
    }

However configuration is always an empty dictionary.

Answer 1

You need to parse the JSON you've as an array of dictionaries of type [[String: Any]]. The better modern approach is to use Decodable model to decode the JSON.

let string = """
[
    {
        "person": "person1",
        "data": {
            "age": "10",
            "name": "John"
        }
    },
    {
        "person": "person2",
        "data": {
            "age": "20",
            "name": "Jonathan"
        }
    },
    {
        "person": "person3",
        "data": {
            "age": "30",
            "name": "Joe"
        }
    }
]
"""

let data = Data(string.utf8)

struct Person: Decodable {
    let person: String
    let data: PersonData
}

struct PersonData: Decodable {
    let age, name: String
}

do {
    let people = try JSONDecoder().decode([Person].self, from: data)
    print(people)
} catch { print(error) }