Convert JSON DATA to useable variables in Swift 3

Question

I currently have code that will take the json data I give it and parse it however I have everything wrapped in a for loop and I don't know how to take it out.

JSON data:

[
{
"id": 1,
"displayName": "Jacob Blacksten",
"department": "DF",
"mamager": "San",
"office": "NYC",
"util": 2
}
]

Working code:

do {
   let json = try JSONSerialization.jsonObject(with: data!, options: .mutableContainers)

      guard let array = json as? [Any] else {return}

      for user in array {
          guard let userDict = user as? [String: Any] else {return}
          guard let id = userDict["id"] as? Int else { return }
          guard let name = userDict["displayName"] as? String else { return}
          guard let department = userDict["department"] as? String else {return}
          guard let manager = userDict["mamager"] as? String else {return}
          guard let office = userDict["office"] as? String else {return}
          guard let util = userDict["util"] as? Int else {return}

                print(id)
                print(name)
                print(department)
                print(manager)
                print(office)
                print(util)
            }

        } catch{
           print(error)
        }

You will notice everything is inside a for loop creating an array of all "users". However I only have one user and I want to be able to pull out say "id" and use it as a variable to later print it out in a label in my app. I hope this makes sense. I basically just want to manipulate this JSON data so that way I can use it and print them in labels in my app.

Why do you assign a type with mutableContainers to an immutable constant (let json)? — vadian
– vadian, Commented Jul 7, 2017 at 19:08

ColdLogic · Accepted Answer · 2017-07-07 19:02:11Z

If you're trying to use your variables elsewhere, you just need to save them to something outside of the scope of your loop. I would suggest creating a User class and saving the values from the json to an instance of User.

// User.swift
class User {
    // Identifier
    let id: Int

    // Instance variables
    var name: String?
    var department: String?
    var manager: String?
    var office: String?
    var util: Int?

    init(withId id: Int) {
        self.id = id
    }
}

Then, you can just change your loop to be something like this.

var user: User?

do {
    let json = try JSONSerialization.jsonObject(with: data!, options: .mutableContainers)

    guard let array = json as? [Any],
      let userDict = array[0] as? [String: Any],
      let id = userDict["id"] as? Int,
      let name = userDict["displayName"] as? String,
      let department = userDict["department"] as? String,
      let manager = userDict["manager"] as? String,
      let office = userDict["office"] as? String,
      let util = userDict["util"] as? Int else { 
        return
    }

    user = User(withId: id)

    user.name = name
    user.department = department
    user.manager = manager
    user.office = office
    user.util = util

} catch{
    print(error)
}

 // Here, the user variable has all the updated info
 userIdLabel?.text = "\(user?.id)"

Note: Did this all in browser, didn't test

Collectives™ on Stack Overflow

Convert JSON DATA to useable variables in Swift 3

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related