Hi there -

Newbie to swift and computer languages with a question about why a particular variable is not updating.

So I'm creating a unit converter app from Challenge Day 19.

I'm using Measurement() to do it. So the basics I have are:

my variables:

    @State var fromAmount = 0.0
    @State var adjustedFromAmount = ""
    @State var toAmount = 0.0
    @State var adjustedToAmount = Measurement(value: 0.0, unit: UnitLength .meters)
    @State var selectedFromUnit = ""
    @State var selectedToUnit = ""
    @State var figuredToUnit: String = ""

my function:

func convertTo(selectedFrom: String, selectedTo: String) {
        if selectedFrom == "meters" {
            switch selectedTo {
            case "feet":
               adjustedToAmount = Measurement(value: fromAmount, unit: .meters).converted(to: UnitLength.feet)
                figuredToUnit = "1"
                toAmount = adjustedToAmount.value
            case "inches":
                adjustedToAmount = Measurement(value: fromAmount, unit: UnitLength.meters).converted(to: UnitLength.inches)
                figuredToUnit = "2"
                toAmount = adjustedToAmount.value
            default:
                adjustedToAmount = Measurement(value: fromAmount, unit: UnitLength.meters)
                figuredToUnit = "3"
                toAmount = adjustedToAmount.value
            }
        } else if selectedFrom == "feet" {
            switch selectedTo {
            case "meters":
                adjustedToAmount = Measurement(value: fromAmount, unit: UnitLength.feet).converted(to: UnitLength.meters)
                figuredToUnit = "4"
                toAmount = adjustedToAmount.value
            case "inches":
                adjustedToAmount = Measurement(value: fromAmount, unit: UnitLength.feet).converted(to: UnitLength.inches)
                figuredToUnit = "5"
                toAmount = adjustedToAmount.value
            default:
                adjustedToAmount = Measurement(value: fromAmount, unit: UnitLength.feet)
                figuredToUnit = "6"
                toAmount = adjustedToAmount.value
            }
        } else if selectedFrom == "inches" {
            switch selectedTo {
            case "feet":
                adjustedToAmount = Measurement(value: fromAmount, unit: UnitLength.inches).converted(to: UnitLength.feet)
                figuredToUnit = "7"
                toAmount = adjustedToAmount.value
            case "meters":
                adjustedToAmount = Measurement(value: fromAmount, unit: UnitLength.inches).converted(to: UnitLength.meters)
                figuredToUnit = "8"
                toAmount = adjustedToAmount.value
            default:
                adjustedToAmount = Measurement(value: fromAmount, unit: UnitLength.inches)
                figuredToUnit = "9"
                toAmount = adjustedToAmount.value
            }
        }

    }

My view looks like:

                    Text("Enter Amount to Convert")
                    TextField("Enter Amount to:", value: $fromAmount, format: .number)
                        .frame(width: /*@START_MENU_TOKEN@*/100/*@END_MENU_TOKEN@*/)
                        .multilineTextAlignment(.trailing)
                        .border(Color.gray)
                        .font(/*@START_MENU_TOKEN@*/.title/*@END_MENU_TOKEN@*/)
                    Text("Select a From Unit")
                    Picker("Select Unit to Convert From", selection: $selectedFromUnit) {
                        ForEach(listOfUnits, id: \.self) {
                            Text($0)
                        }
                    }
                  /* .onChange(of: selectedFromUnit){
                     convertTo(selectedFrom: selectedFromUnit, selectedTo: selectedToUnit)
                    }*/
                    .pickerStyle(.segmented)
                    Text("Select a To Unit")
                    Picker("Select Unit to Convert To", selection: $selectedToUnit) {
                            ForEach(listOfUnits, id: \.self) {
                                Text($0)
                            }
                        }
                     /*   .onChange(of: selectedToUnit){
                            convertTo(selectedFrom: selectedFromUnit, selectedTo: selectedToUnit)
                        }*/
                        .pickerStyle(.segmented)
                    Button("Convert"){
                        convertTo(selectedFrom: selectedFromUnit, selectedTo: selectedToUnit)
                    }

I call the function in a button:

Button("Convert"){
                        convertTo(selectedFrom: selectedFromUnit, selectedTo: selectedToUnit)
                    }

Then I uses Text() to show my results:

Text("\(adjustedToAmount.formatted(unitStyle))")
                    .font(.largeTitle)
                Text("\(figuredToUnit)")
                Text("\(toAmount)")

The funny thing that happens is as I start changing my units it stops converting. So the variable adjustedToAmount stops updating, but the variable figuredToUnit continues to show the correct evaulation as I change my From/To units.

As you can I tried the onChange() but that is when I first started noticing the issue. I thought maybe a button would fix it, but it hasn't.

Look forward to learning what is the cause of this and more about swift.

Thanks,