how to select select and use the properties of the instance of the struct selected

You did not format all code with code formatter, it is really hard to understand.

how do i select one favorite, and how can i acces the properties of the struct selected

When you select in a list, you select a String: see here: https://www.hackingwithswift.com/quick-start/swiftui/how-to-allow-row-selection-in-a-list

Change

  var body: some View {
     
    NavigationView {
      VStack{
        List
        { ForEach(favoritos.favs) { drug in
          Text("\(drug.name) \(drug.amount) \(drug.unitamount) en \(drug.bag)")
        }

To

    @State private var selection: String?

    var body: some View {
        NavigationView {
            List(favoritos.favs, id: \.self, selection: $selection) { drug in
          Text("\(drug.name) \(drug.amount) \(drug.unitamount) en \(drug.bag)")
            }

So to find which it is, you have to find which corresponds to the String.

What you get is the String defined here

          "\(drug.name) \(drug.amount) \(drug.unitamount) en \(drug.bag)"

So, you could

• parse this String to find the first word => drugName
• filter favoritos.favs

let selected = favoritos.favs.filter { $0.name.contains(drugName) }

Then you access selected properties: selected.bag for instance.

Thanks Claude31 Below is the whole code of the two views I have so far I tried your suggestion but i didn't get what i need, so i commented it out when i changed the code i couldn't select any row My objective is to be able to create instances of the DRUG struct in addView that are added to my favorites list in favView, I managed that so far. My next goal is to be able to select a row from my favorite list and be able to use that specific instance of the struct in another place

import SwiftUI

struct Drug: Identifiable, Codable, Hashable {
  var id = UUID()
  var name: String
  var amount: String
  var unitamount : String
  var bag: String
  
 var isRead: Bool = false
}





 class Favoritos: ObservableObject {
 @Published var favs = [Drug]() {
   didSet {
     if let encoded = try? JSONEncoder().encode(favs) {
       UserDefaults.standard.set(encoded, forKey: "Favs")
     }
   }
 }
   init() {
     if let savedItems = UserDefaults.standard.data(forKey: "Favs") {
       if let decodedItems = try? JSONDecoder().decode([Drug].self, from: savedItems) {
        favs = decodedItems
         return
       }
     }

     favs = []
   }
}

struct FavListView: View {
  @StateObject var favoritos = Favoritos()
//  @State var newdrug = Drug(name: "", amount: "", bag: "")
  @State private var showingAddView = false
  func removeItems(at offsets: IndexSet) {
    favoritos.favs.remove(atOffsets: offsets)
  }
  @State private var selection: String?

  var body: some View {
     
    NavigationView {
      VStack{
//        List {
//          TextField ("Droga", text: $newdrug.name)
//          TextField ("Cantidad", text: $newdrug.amount)
//          TextField ("Volumen", text: $newdrug.bag)
//        }
    
//        List(favoritos.favs, id: \.self, selection: $selection) { drug in
//             Text("\(drug.name) \(drug.amount) \(drug.unitamount) en \(drug.bag)")
//              }
//        .toolbar {
//          EditButton()
//        }
         
        List
        { ForEach(favoritos.favs) { drug in
          Text("\(drug.name) \(drug.amount) \(drug.unitamount) en \(drug.bag)")

        }.onDelete(perform: removeItems)

        }.navigationTitle("Infusiones favoritas")
          .navigationBarTitleDisplayMode(.inline)
          .accentColor(.black)

          .toolbar {
            EditButton()
          }
         
        Button ("agregar nuevo favorito") {showingAddView = true }
       
//        Button ("Add") {
//        favoritos.favs.insert(Drug(name: newdrug.name, amount: newdrug.amount, bag: newdrug.bag), at: 0)
//
//
//                }
         
      }.sheet(isPresented: $showingAddView) {
        AddView(favoritos: favoritos)
       
    }
    }
     
  }
     
    struct FavListView_Previews: PreviewProvider {
      static var previews: some View {
        FavListView()
      }
    }
  }

import SwiftUI

struct AddView: View {
  @ObservedObject var favoritos : Favoritos
  @State var newdrug = Drug(name: "", amount: "", unitamount: "", bag: "")
   
  var body: some View {
    VStack{
      List {
        TextField ("Droga", text: $newdrug.name)
          .disableAutocorrection(/*@START_MENU_TOKEN@*/true/*@END_MENU_TOKEN@*/)
        TextField ("Cantidad", text: $newdrug.amount)
        TextField ("Unidad", text: $newdrug.unitamount)
          .autocapitalization(/*@START_MENU_TOKEN@*/.none/*@END_MENU_TOKEN@*/)
        TextField ("Volumen", text: $newdrug.bag)
      }
       
      
         
      }
       
       
      Button ("Add") {
        favoritos.favs.insert(Drug(name: newdrug.name, amount: newdrug.amount, unitamount: newdrug.unitamount, bag: newdrug.bag), at: 0)
         
        
              }
       
    }
  }


struct AddView_Previews: PreviewProvider {
  static var previews: some View {
    AddView(favoritos : Favoritos())
  }
}

Any Help? I dont understand why i cant select a row