When I try to run my code I get the following error: Trailing closure passed to parameter of type 'FormStyleConfiguration' that does not accept a closure. I am certain its from the picker I am using in the code. How do I fix this?

Here is the code:

//
//  ContentView.swift
//  BetterRest
//

import CoreML
import SwiftUI

struct ContentView: View
{
    @State private var wakeUp = defaultWakeTime
    @State private var sleepAmount = 8.0
    @State private var coffeeAmount = 1

    @State private var alertTitle = ""
    @State private var alertMessage = ""
    @State private var showingAlert = false

    static var defaultWakeTime: Date
    {
        var components = DateComponents()
        components.hour = 7
        components.minute = 0
        return Calendar.current.date(from: components) ?? Date.now
    }

    var body: some View
    {
        NavigationView
        {
            Form
            {
                Section
                {
                    Text("When do you want to wake up")
                        .font(.headline)
                    DatePicker("Please enter a time", selection: $wakeUp, displayedComponents: .hourAndMinute)
                        .labelsHidden()
                }

                Section
                {
                    Text("Desired amout of sleep")
                        .font(.headline)

                    Stepper("\(sleepAmount.formatted()) hours", value: $sleepAmount, in: 4...12, step: 0.25)
                }

                Section
                {
//                    Text("Daily coffeee intake")
//                        .font(.headline)

                    Picker("Daily coffee intake", selection: $coffeeAmount)
                        .font(.headline)
                    {
                        ForEach(1..<21)
                        { myCoffeeAmount in
                            Text(myCoffeeAmount == 1 ? "1 cup" : "\(myCoffeeAmount) cups")
                        }
                    }
                }
            }
            .navigationTitle("BetterRest")
            .toolbar
            {
                Button("Calculate", action: calculateBedtime)
            }
            .alert(alertTitle, isPresented: $showingAlert) {
                Button("OK") { }
            } message: {
                Text(alertMessage)
            }
        }
    }

    func calculateBedtime()
    {
       do
       {
           let config = MLModelConfiguration()
           let model = try SleepCalculator(configuration: config)

           let components = Calendar.current.dateComponents([.hour, .minute], from: wakeUp)

           let hour = (components.hour ?? 0) * 60 * 60
           let minute = (components.minute ?? 0) * 60

           let prediction = try model.prediction(wake: Int64(hour + minute), estimatedSleep: sleepAmount, coffee: Int64(coffeeAmount))

           let sleepTime = wakeUp - prediction.actualSleep
           alertTitle = "Your ideal bedtime is..."
           alertMessage = sleepTime.formatted(date: .omitted, time: .shortened)

       } catch {
           alertTitle = "Error"
           alertMessage = "Sorry, there was a problem calculating your bedtime."
       }
        showingAlert = true
    }
}

struct ContentView_Previews: PreviewProvider
{
    static var previews: some View
    {
        ContentView()
    }
}

Here is the line of code giving me problems:

Section
                {

                    Picker("Daily coffee intake", selection: $coffeeAmount)
                        .font(.headline)
                    {
                        ForEach(1..<21)
                        { myCoffeeAmount in
                            Text(myCoffeeAmount == 1 ? "1 cup" : "\(myCoffeeAmount) cups")
                        }
                    }
                }

I tried changing the picker to this but it still does not work:

Section
                {

                    Picker("Daily coffee intake", selection: $coffeeAmount)
                        .font(.headline)
                    {
                        ForEach(1..<21)
                        {
                            Text($0 == 1 ? "1 cup" : "\($0) cups")
                        }
                    }
                }

So when I add a pickerstyle to the code it compiles but it still gives me the following warning: 1. 'init(_:)' declared here (SwiftUI.Form)

Also my code starts with 2 cups of coffee instead of just one. Not sure why its doing this.

Section
                {

                    Picker("Daily coffee intake", selection: $coffeeAmount)
                    {
                        ForEach(1..<21)
                        {
                            Text($0 == 1 ? "1 cup" : "\($0) cups")
                        }
                    }
                    .pickerStyle(.automatic)
                    .font(.headline)
                }

When I change ForEach to (0..<21) I start at 1 cup but when I use ForEach(1..<21) it starts at 2.

Hi, so as you probably noticed you cannot apply font modifier to the picker like so:

 Picker("Daily coffee intake", selection: $coffeeAmount)
                        .font(.headline)

but only after a closure it takes:

Picker("Daily coffee intake", selection: $coffeeAmount)
                    {
                        ForEach(1..<21)
                        {
                            Text($0 == 1 ? "1 cup" : "\($0) cups")
                        }
                    }
                    .pickerStyle(.automatic)
                    .font(.headline) // <- font modifier applied here

To solve the second issue the easiest way is to create array of numbers after your @State properties like that:

let numberOfCoffeeCups = Array(1...20)

and use it in your picker similar to this.

Picker("Number of cups", selection: $coffeeAmount) {
                        ForEach(numberOfCoffeeCups, id: \.self) {
                            Text($0, format: .number)
                        }
                    }

What about this error? What do I do about it?

1. 'init(_:)' declared here (SwiftUI.Form),

The error happens after my first form after navigation view.

Here is the code of the solution of your problem

{

                Picker("Daily coffee intake", selection: $coffeeAmount)
                    .font(.headline)
                {
                    ForEach(1..<21)
                    { myCoffeeAmount in
                        Text(myCoffeeAmount == 1 ? "1 cup" : "\(myCoffeeAmount) cups")
                    }
                }
            }