I'm trying to get pokemon names from the pokeApi, but I have this error :

"No value associated with key CodingKeys(stringValue: "index", intValue: nil) ("index").", underlyingError: nil

import UIKit

class ListViewController: UIViewController {
    @IBOutlet weak var pokemon1: UILabel!
    @IBOutlet weak var pokemon2: UILabel!
    @IBOutlet weak var pokemon3: UILabel!
    @IBOutlet weak var pokemon4: UILabel!
    @IBOutlet weak var pokemon5: UILabel!
    
    let url = "https://pokeapi.co/api/v2/pokemon"
    
    override func viewDidLoad() {
        super.viewDidLoad()
        fetchData(from: url)
    }
    
    
    
    func fetchData(from url: String) {
        let url = URL(string: url)
        let defaultSession = URLSession(configuration: .default)
        let dataTask = defaultSession.dataTask(with: url!) { (data: Data?, response: URLResponse?, error: Error?) in
            if(error != nil) {
                print(String(describing: error))
                return
            }
            
            var json: Pokemon
            
            do {
                json = try JSONDecoder().decode(Pokemon.self, from: data!)
                Swift.print(json)
                
//                DispatchQueue.main.async {
//                    self.pokemon1.text = json.name
//                    self.pokemon3.text = json[2].name
//                    self.pokemon4.text = json[3].name
//                    self.pokemon5.text = json[4].name
//                    //callback: fonction que j'appelle à la suite d'un évènement
//                }
            } catch {
                print(error)
                return
            }
        }
        dataTask.resume() // Commence la dataTask si elle n'est pas en marche actuellement
    }
    
    struct Pokemon: Codable {
        let results: Results
    }
    
    struct Results: Codable {
        let name: String
        let index: String
    }
}

Here's the data from the api link:

{
  "count": 1154,
  "next": "https://pokeapi.co/api/v2/pokemon?offset=20&limit=20",
  "previous": null,
  "results": [
    {
      "name": "bulbasaur",
      "url": "https://pokeapi.co/api/v2/pokemon/1/"
    },
    {
      "name": "ivysaur",
      "url": "https://pokeapi.co/api/v2/pokemon/2/"
    },
    {
      "name": "venusaur",
      "url": "https://pokeapi.co/api/v2/pokemon/3/"
    },
    {
      "name": "charmander",
      "url": "https://pokeapi.co/api/v2/pokemon/4/"
    },
    {
      "name": "charmeleon",
      "url": "https://pokeapi.co/api/v2/pokemon/5/"
    },
    {
      "name": "charizard",
      "url": "https://pokeapi.co/api/v2/pokemon/6/"
    },
    {
      "name": "squirtle",
      "url": "https://pokeapi.co/api/v2/pokemon/7/"
    },
    {
      "name": "wartortle",
      "url": "https://pokeapi.co/api/v2/pokemon/8/"
    },
    {
      "name": "blastoise",
      "url": "https://pokeapi.co/api/v2/pokemon/9/"
    },
    {
      "name": "caterpie",
      "url": "https://pokeapi.co/api/v2/pokemon/10/"
    },
    {
      "name": "metapod",
      "url": "https://pokeapi.co/api/v2/pokemon/11/"
    },
    {
      "name": "butterfree",
      "url": "https://pokeapi.co/api/v2/pokemon/12/"
    },
    {
      "name": "weedle",
      "url": "https://pokeapi.co/api/v2/pokemon/13/"
    },
    {
      "name": "kakuna",
      "url": "https://pokeapi.co/api/v2/pokemon/14/"
    },
    {
      "name": "beedrill",
      "url": "https://pokeapi.co/api/v2/pokemon/15/"
    },
    {
      "name": "pidgey",
      "url": "https://pokeapi.co/api/v2/pokemon/16/"
    },
    {
      "name": "pidgeotto",
      "url": "https://pokeapi.co/api/v2/pokemon/17/"
    },
    {
      "name": "pidgeot",
      "url": "https://pokeapi.co/api/v2/pokemon/18/"
    },
    {
      "name": "rattata",
      "url": "https://pokeapi.co/api/v2/pokemon/19/"
    },
    {
      "name": "raticate",
      "url": "https://pokeapi.co/api/v2/pokemon/20/"
    }
  ]
}

I think I have an error from the structures... I don't really know if I need to put an array and where to put it in the code ?

CodePudding user response：

You're right, you need an array in your data structure. The results key is for an array of Results, not a single entity.

For some reason you are also using index rather than url for the field name in Result.

This should work (note: renamed Results to Result as it's a single item)

    struct Pokemon: Codable {
        let results: [Result]
    }
    
    struct Result: Codable {
        let name: String
        let url: String
    }