How to get the key value from the String of JSON in swift

Question

I have a JSON string value how to get the key value from the json using swift code?

{ 
 "user":{  "id":"74d93200-2ed2-437c-976f-83710eaea923","firstName":"dev","lastName":"che", "username":"dev_che"}}

From this how to get the "username" value using swift code?

Mac3n · Answer 1 · 2020-02-19T12:28:58.207

2

first define User struct

struct UserModel: Codable {
    let user: User?
}

struct User: Codable {
    let id, firstName, lastName, username: String?
}

then decode your model from json

let userData =
            "{\"user\":{\"id\":\"74d93200-2ed2-437c-976f-83710eaea923\",\"firstName\":\"dev\",\"lastName\":\"che\", \"username\":\"dev_che\"}}"
        let data = userData.data(using: .utf8)!
        let userModel = try? JSONDecoder().decode(UserModel.self, from: data)

then you can use it this way :


userModel.username

edited Feb 19 '20 at 12:28

answered Feb 19 '20 at 11:17

Mac3n

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jsonData should be of which type? As I give it as String I get the error as Cannot convert value of type 'String' to expected argument type 'Data' – Mahalakshmi Saravanan Feb 19 '20 at 11:23
@MahalakshmiSaravanan it needs to be `Data` so you must `guard let jsonData = text.data(using: .utf8) else { return }` do this first. Also [Mac3n](https://stackoverflow.com/users/9743184/mac3n)'s answer is correct but if you don't want to go with `Codable` approach then [this](https://stackoverflow.com/questions/30480672/how-to-convert-a-json-string-to-a-dictionary) might help. – Ayazmon Feb 19 '20 at 11:24
@Ayazmon I am getting the values as nil UserDetails(id: nil, firstName: nil, lastName: nil, username: nil)) – Mahalakshmi Saravanan Feb 19 '20 at 12:10
@Mac3n userModel.username using this code not able to get the username as I get the error as Value of type 'UserModel?' has no member 'username' – Mahalakshmi Saravanan Feb 20 '20 at 06:00
try userModel.user.username – Mac3n Feb 20 '20 at 06:21
getting the value as nil – Mahalakshmi Saravanan Feb 20 '20 at 06:23
Did you try my example. it test it and it’s work correctly. check your data source. please test it with userData json string – Mac3n Feb 20 '20 at 06:26
Thanks I am able to retrieve my username details – Mahalakshmi Saravanan Feb 20 '20 at 10:41

How to get the key value from the String of JSON in swift

1 Answers1