SwiftUI iterating through dictionary with ForEach

Question

Is there a way to iterate through a Dictionary in a ForEach loop? Xcode says

Generic struct \'ForEach\' requires that \'[Str

Answer 1

Here is how I implemented this:

struct CartView: View {
    var cart:[String: Int]

    var body: some View {
        List {
            ForEach(cart.keys.sorted()) { key in
                Text(key)
                Text("\(cart[key]!)")
            }
        }
    }
}

The first Text View will output the key which is a String. The second Text View will output the value of the Dict at that key which is an Int. The ! that follows this is to unwrap the Optional which contains this Int. In production you would perform checks on this Optional for a more safe way of unwrapping it, but this is a proof of concept.

Answer 2

Xcode: 11.4.1~

    ...
    var testDict: [String: Double] = ["USD:": 10.0, "EUR:": 10.0, "ILS:": 10.0]
    ...
    ForEach(testDict.keys.sorted(), id: \.self) { key in
        HStack {
            Text(key)
            Text("\(testDict[key] ?? 1.0)")
        }
    }
    ...

more detail:

final class ViewModel: ObservableObject {
    @Published
    var abstractCurrencyCount: Double = 10
    @Published
    var abstractCurrencytIndex: [String: Double] = ["USD:": 10.0, "EUR:": 15.0, "ILS:": 5.0]
}

struct SomeView: View {
    @ObservedObject var vm = ViewModel()
    var body: some View {
        NavigationView {
            List {
                ForEach(vm.abstractCurrencytIndex.keys.sorted(), id: \.self) { key in
                    HStack {
                        Text(String(format: "%.2f", self.vm.abstractCurrencyCount))
                        Text("Abstract currency in \(key)")
                        Spacer()
                        Text(NumberFormatter.localizedString(from: NSNumber(value: self.vm.abstractCurrencytIndex[key] ?? 0.0), number: .currency))
                    }
                }
            }
        }
    }
}

Answer 3

Since it's unordered, the only way is to put it into an array, which is pretty simple. But the order of the array will vary.

struct Test : View {
let dict: [String: Int] = ["test1": 1, "test2": 2, "test3": 3]
var body: some View {
    let keys = dict.map{$0.key}
    let values = dict.map {$0.value}

    return List {
        ForEach(keys.indices) {index in
            HStack {
                Text(keys[index])
                Text("\(values[index])")
            }
        }
    }
}
}

#if DEBUG
struct Test_Previews : PreviewProvider {
    static var previews: some View {
        Test()
    }
}
#endif

Answer 4

The syntax errors I encountered using code from some of the answers to this post helped me sort out a solution for my own problem...

Using a dictionary that contained:

• key = a CoreDataEntity;
• value = the count of instances of that entity from a relationship (type NSSet).

I highlight the answer by @J.Doe and comments that an unordered / random collection Dictionary may not be the best solution to use with table view cells (AppKit NSTableView / UIKit UITableView / SwiftUI List rows).

Subsequently, I'll be rebuilding my code to instead work with arrays.

But if you must work with a Dictionary, here is my working solution:

struct MyView: View {
    
    var body: some View {
        
        // ...code to prepare data for dictionary...

        var dictionary: [CoreDataEntity : Int] = [:]

        // ...code to create dictionary...

        let dictionarySorted = dictionary.sorted(by: { $0.key.name < $1.key.name })
        // where .name is the attribute of the CoreDataEntity to sort by
        
        VStack {  // or other suitable view builder/s
            ForEach(dictionarySorted, id: \.key) { (key, value) in
                Text("\(value) \(key.nameSafelyUnwrapped)")
            }
        }
    }
}

extension CoreDataEntity {
    var nameSafelyUnwrapped: String {
        guard let name = self.name else {
            return String() // or another default of your choosing
        }
        return name
    }
}

Answer 5

You can sort your dictionary to get (key, value) tuple array and then use it.

struct ContentView: View {
    let dict = ["key1": "value1", "key2": "value2"]
    
    var body: some View {
        List {
            ForEach(dict.sorted(by: >), id: \.key) { key, value in
                Section(header: Text(key)) {
                    Text(value)
                }
            }
        }
    }
}

Answer 6

I was trying to figure this out as well with a Dictionary of enum/Int pairs. I am effectively converting it to array as Andre suggests, but instead of using map I just cast the keys.

enum Fruits : Int, CaseIterable {
    case Apple = 0
    case Banana = 1
    case Strawberry = 2
    case Blueberry = 3
}

struct ForEachTest: View {
    var FruitBasket : [Fruits: Int] = [Fruits.Apple: 5, Fruits.Banana : 8, Fruits.Blueberry : 20]
    var body: some View {
        VStack {
            ForEach([Fruits](FruitBasket.keys), id:\Fruits.hashValue) { f in
                Text(String(describing: f) + ": \(self.FruitBasket[f]!)")
            }
        }
    }
}

struct ForEachTest_Previews: PreviewProvider {
    static var previews: some View {
        ForEachTest()
    }
}