Good afternoon all,

I am trying to add a left bar button that calls startGame( ), but am not having much success.

After reviewing my prior notes/code, I am able to add a button to the navigation bar, and have it print, but am having trouble when it comes to calling a function.

Under NavigationView, directly below .navigationBarTitle(rootWord) is wrote the following, where I am trying to have the code call the function startGame( )

 .navigationBarItems(leading: Button(.add, target: self, action: #selector(startGame)))

Swift doesnt like this approach, so really appreciate thoughts/advice on how to write it so that the button calls startGame(), so that a user can restart with a new word whenever they want.

full code is as follows, just so it's available for review if necessary....

import SwiftUI

struct ContentView: View {
    @State private var usedWords = [String]()
    @State private var rootWord = ""
    @State private var newWord = ""

    @State private var errorTitle = ""
    @State private var errorMessage = ""
    @State private var showingError = false

    var body: some View {
        NavigationView {
            VStack {
                TextField("Enter your word", text: $newWord, onCommit: addNewWord)
                    .textFieldStyle(RoundedBorderTextFieldStyle())
                    .autocapitalization(.none)
                    .padding()

                List(usedWords, id: \.self) {
                    Image(systemName: "\($0.count).circle")
                    Text($0)

                }
            }
            .navigationBarTitle(rootWord)

            .navigationBarItems(leading: Button(.add, target: self, action: #selector(startGame)))

            .onAppear(perform: startGame)
            .alert(isPresented: $showingError) {
                Alert(title: Text(errorTitle), message: Text(errorMessage), dismissButton:
                        .default(Text("OK")))
            }
        }
    }
    func addNewWord() {
        let answer = newWord.lowercased()
            .trimmingCharacters(in:.whitespacesAndNewlines)

        guard answer.count > 0 else {
            return
        }

        guard isOriginal(word: answer) else {
            wordError(title: "Word used already", message: "Please be more original")
            return
        }

        guard isPossible(word: answer) else {
            wordError(title: "Word not recognized", message: "You can't just make them up")
            return
        }

        guard isReal(word: answer) else {
                wordError(title: "Word not possible", message: "That isn't a real word")
            return
       }

        guard answer.count >= 3 else {
            wordError(title: "Word isn't possible", message: "It is less than 3 characters")
            return
        }

       // guard isReal(word: answer) else {
       //     wordError(title: "Word not possible", message: "That isn't a real word")
       //     return
      //  }

        usedWords.insert(answer, at: 0)
        newWord = ""
    }

    func startGame() {
        if let startWordsURL =
            Bundle.main.url(forResource: "start", withExtension: "txt") {
            if let startWords = try?
                String(contentsOf: startWordsURL) {
                let allWords =
                    startWords
                    .components(separatedBy: "\n")
                rootWord = allWords.randomElement()
                    ?? "silkworm"
                return
            }
        }
        fatalError("Could not load start.txt from bundle.")
    }

    func isOriginal(word: String) -> Bool {
        !usedWords.contains(word)
    }

    func isPossible(word: String) -> Bool {
        var tempWord = rootWord.lowercased()

        for letter in word {
            if let pos = tempWord.firstIndex(of: letter) {
                tempWord.remove(at: pos)
            } else {
                return false
            }
        }
        return true
    }

    func isReal(word: String) -> Bool {

        let checker = UITextChecker()
    let range = NSRange(location: 0, length: word.utf16.count)
        let misspelledRange = checker.rangeOfMisspelledWord(in: word, range: range, startingAt: 0, wrap: false, language: "en")

        return misspelledRange.location == NSNotFound
    }

    func wordError(title: String, message: String) {
        errorTitle = title
        errorMessage = message
        showingError = true
    }
}

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

Use .toolbar instead of .navigationBarItems (this is depreciated in iOS14)

.toolbar {
    ToolbarItem(placement: .navigationBarLeading) {
        Button("Start Game", action: startGame)
    }
}

thanks guys!

really appreciate the help.