.swift

struct ContentView: View {
    
    @State private var isOn: Bool = false
    
    var body: some View {
        
        return VStack {
        
            Text(self.isOn ? "🌞" : "🌙")
                           .font(.custom("Arial", size: 100))
            
            DayNightView(isOn: $isOn)
            
        }
        
    }
}