100 days of swiftui: challenge
https://www.hackingwithswift.com/100/swiftui/19

challenge

You need to build an app that handles unit conversions: users will select an input unit and an output unit, then enter a value, and see the output of the conversion.

✅ Time conversion: users choose seconds, minutes, hours, or days.

If you were going for length conversion you might have:

• A segmented control for seconds, minutes, hours, or days, for the input unit.
• A second segmented control for seconds, minutes, hours, or days, for the output unit.
• A text field where users enter a number.
• A text view showing the result of the conversion.

solution

import SwiftUI

enum typeOfTime {
    case Day, Hour, Minute, Second
}

struct ContentView: View {
    @State private var timeAmount = 0
    @State private var typeOfTimeInput = typeOfTime.Hour
    @State private var typeOfTimeOutput = typeOfTime.Minute
    let typesOfTime = [typeOfTime.Day, typeOfTime.Hour, typeOfTime.Minute, typeOfTime.Second]
    var timeConverted: Double {
        if typeOfTimeInput == typeOfTimeOutput {
            return Double(timeAmount)
        } else if typeOfTimeInput == .Day && typeOfTimeOutput == .Hour { // Day to
            return Double(timeAmount) * 24
        } else if typeOfTimeInput == .Day && typeOfTimeOutput == .Minute {
            return Double(timeAmount) * 24 * 60
        } else if typeOfTimeInput == .Day && typeOfTimeOutput == .Second {
            return Double(timeAmount) * 24 * 60 * 60
        } else if typeOfTimeInput == .Hour && typeOfTimeOutput == .Day { // Hour to
            return Double(timeAmount) / 24
        } else if typeOfTimeInput == .Hour && typeOfTimeOutput == .Minute {
            return Double(timeAmount) * 60
        } else if typeOfTimeInput == .Hour && typeOfTimeOutput == .Second {
            return Double(timeAmount) * 60 * 60
        } else if typeOfTimeInput == .Minute && typeOfTimeOutput == .Day { // Minute to
            return Double(timeAmount) / 60 / 24
        } else if typeOfTimeInput == .Minute && typeOfTimeOutput == .Hour {
            return Double(timeAmount) / 60
        } else if typeOfTimeInput == .Minute && typeOfTimeOutput == .Second {
            return Double(timeAmount) * 60
        } else if typeOfTimeInput == .Second && typeOfTimeOutput == .Day { // Second to
            return Double(timeAmount) / 60 / 60 / 24
        } else if typeOfTimeInput == .Second && typeOfTimeOutput == .Hour {
            return Double(timeAmount) / 60 / 60
        } else {
            return Double(timeAmount) / 60
        }
    }
    var body: some View {
        NavigationStack {
            Form {
                Section("Input") {
                    Picker("typeOfTime", selection: $typeOfTimeInput) {
                        ForEach(typesOfTime, id: \.self) {
                            Text("\($0)")
                        }
                    }
                    .pickerStyle(.segmented)
                    TextField("Amount", value: $timeAmount, format: .number)
                }
                Section("Output") {
                    Picker("typeOfTime", selection: $typeOfTimeOutput) {
                        ForEach(typesOfTime, id: \.self) {
                            Text("\($0)")
                        }
                    }
                    .pickerStyle(.segmented)
                    Text(timeConverted, format: .number)
                }
            }
            .navigationTitle("Time Conversion")
        }
    }
}

• Input, Output을 Section으로 구분했다.
• 오타를 방지하고자 time의 type을enum으로 설정했다. 그리고 ForEach()에서 요소를 나타낼 때는 Text로 변환하여 보여줬다.
• 입력된 값을 원하는 형태의 type 값으로 계산하여 timeConverted로 표현했다.

코드 파일
https://github.com/treesofgroo/Ios-WeSplit/blob/main/TimeConversion/TimeConversion/ContentView.swift