## Day 19 Solution

 Mar '23 Here's my solution for the challenge. I tried my best to use simple concepts with as much efficiency as I could think of. I also tried to change the values of the inputUnit and outputUnit state variable so whenever the user chooses a different conversion type, it will pick the first two units of that type. But I couldn't figure that out so I finished the challenge without doing so. Please feel free to give any advices or suggestions. and sorry if the code hurts your eyes 😅 ``````import SwiftUI struct ContentView: View { // conversion types and units arrays let coversionTypes = ["temp", "length", "time", "volume"] let temperatureUnits = ["celsius", "fahrenheit", "kelvin"] let lengthUnits = ["meters", "km", "feet", "yards", "miles"] let timeUnits = ["seconds", "minutes", "hours", "days"] let volumeUnits = ["ml", "liters", "cups", "pints", "gallons"] // state variables @State private var coversionType = "temp" @State private var inputUnit = "celsius" @State private var outputUnit = "fahrenheit" @State private var inputValue = 0.0 @FocusState private var inputValueIsFocused: Bool // computed property to display units based on chosen conversion type var conversionUnits: [String] { switch coversionType { case "temp": return temperatureUnits case "length": return lengthUnits case "time": return timeUnits default: return volumeUnits } } // computed property to convert from any input to celsius var tempCelsius: Measurement { switch inputUnit { case "fahrenheit": return Measurement(value: inputValue, unit: UnitTemperature.fahrenheit).converted(to: .celsius) case "kelvin": return Measurement(value: inputValue, unit: UnitTemperature.kelvin).converted(to: .celsius) default: return Measurement(value: inputValue, unit: UnitTemperature.celsius) } } // computed property to convert from any input to meters var lengthMeters: Measurement { switch inputUnit { case "km": return Measurement(value: inputValue, unit: UnitLength.kilometers).converted(to: .meters) case "feet": return Measurement(value: inputValue, unit: UnitLength.feet).converted(to: .meters) case "yards": return Measurement(value: inputValue, unit: UnitLength.yards).converted(to: .meters) case "miles": return Measurement(value: inputValue, unit: UnitLength.miles).converted(to: .meters) default: return Measurement(value: inputValue, unit: UnitLength.meters) } } // computed property to convert from any input to seconds var timeSeconds: Measurement { switch inputUnit { case "minutes": return Measurement(value: inputValue, unit: UnitDuration.minutes).converted(to: .seconds) case "hours": return Measurement(value: inputValue, unit: UnitDuration.hours).converted(to: .seconds) case "days": return Measurement(value: inputValue * 24, unit: UnitDuration.hours).converted(to: .seconds) // no day unit! default: return Measurement(value: inputValue, unit: UnitDuration.seconds) } } // computed property to convert from any input to milliliters var volumeMl: Measurement { switch inputUnit { case "liters": return Measurement(value: inputValue, unit: UnitVolume.liters).converted(to: .milliliters) case "cups": return Measurement(value: inputValue, unit: UnitVolume.cups).converted(to: .milliliters) case "pints": return Measurement(value: inputValue, unit: UnitVolume.pints).converted(to: .milliliters) case "gallons": return Measurement(value: inputValue, unit: UnitVolume.gallons).converted(to: .milliliters) default: return Measurement(value: inputValue, unit: UnitVolume.milliliters) } } // computed property to convert from any base value to the chosen output unit var outputValue: Double { switch outputUnit { // temp cases (c to x) case "celsius": return tempCelsius.value case "fahrenheit": return tempCelsius.converted(to: .fahrenheit).value case "kelvin": return tempCelsius.converted(to: .kelvin).value // length cases (meters to x) case "meters": return lengthMeters.value case "km": return lengthMeters.converted(to: .kilometers).value case "feet": return lengthMeters.converted(to: .feet).value case "yards": return lengthMeters.converted(to: .yards).value case "miles": return lengthMeters.converted(to: .miles).value // time cases (seconds to x) case "seconds": return timeSeconds.value case "minutes": return timeSeconds.converted(to: .minutes).value case "hours": return timeSeconds.converted(to: .hours).value case "days": return timeSeconds.converted(to: .hours).value / 24 // no day unit! // volume cases (ml to x) case "ml": return volumeMl.value case "liters": return volumeMl.converted(to: .liters).value case "cups": return volumeMl.converted(to: .cups).value case "pints": return volumeMl.converted(to: .pints).value case "gallons": return volumeMl.converted(to: .gallons).value // default (return input value) default: return inputValue } } var body: some View { NavigationView { Form { // conversion picker Section { Picker("Coversion Type", selection: \$coversionType) { ForEach(coversionTypes, id: \.self) { Text(\$0) } }.pickerStyle(.segmented) } header: { Text("Choose conversion type") } // input Section { Picker("Input Unit", selection: \$inputUnit) { ForEach(conversionUnits, id: \.self) { Text(\$0) } }.pickerStyle(.segmented) TextField("Input Value", value: \$inputValue, format: .number) .keyboardType(.decimalPad) .focused(\$inputValueIsFocused) } header: { Text("Choose input unit & enter input value") } // output Section { Picker("Output Unit", selection: \$outputUnit) { ForEach(conversionUnits, id: \.self) { Text(\$0) } }.pickerStyle(.segmented) Text(outputValue.formatted()) } header: { Text("Choose output unit") } // nav title, toolbar to hide keyboard } .navigationTitle("Units Converter") .toolbar { ToolbarItemGroup(placement: .keyboard) { Spacer() Button("Done") { inputValueIsFocused = false } } } } } }``````

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