let gamePlayChoicesArr: [String] = ["rock", "paper", "scissors"]
var gameOn: Bool = true

    while gameOn {
        print("Let's go! Rock, paper, scissors...the choice is yours.")
        var playerResponse: String = readLine()!
        var randomIndex: Int = Int(arc4random_uniform(UInt32(gamePlayChoicesArr.count)))
        var compilerPlayerResponse = gamePlayChoicesArr[randomIndex]

        if playerResponse == compilerPlayerResponse {
            print("Opponent: \(compilerPlayerResponse)")
            print("You have tied! Play again? Please respond with yes or no.")
        } else if playerResponse == "rock" && compilerPlayerResponse == "scissors" {
            print("Opponent: \(compilerPlayerResponse)")
            print("You win! Play again? Please respond with yes or no.")
        } else if playerResponse == "rock" && compilerPlayerResponse == "paper" {
            print("Opponent: \(compilerPlayerResponse)")
            print("You lose! Play again? Please respond with yes or no.")
        } else if playerResponse == "paper" && compilerPlayerResponse == "rock" {
            print("Opponent: \(compilerPlayerResponse)")
            print("You win! Play again? Please respond with yes or no.")
        } else if playerResponse == "paper" && compilerPlayerResponse == "scissors" {
            print("Opponent: \(compilerPlayerResponse)")
            print("You lose! Play again? Please respond with yes or no.")
        } else if playerResponse == "scissors" && compilerPlayerResponse == "paper" {
            print("Opponent: \(compilerPlayerResponse)")
            print("You win! Play again? Please respond with yes or no.")
        } else if playerResponse == "scissors" && compilerPlayerResponse == "rock" {
            print("Opponent: \(compilerPlayerResponse)")
            print("You lose! Play again? Please respond with yes or no.")
        } else if playerResponse != "rock" || playerResponse != "scissors" || playerResponse != "paper" {
            print("Please enter a valid response.")
            continue
        }

        var doYouWantToPlayResponse = readLine()!

            if doYouWantToPlayResponse == "yes" {
                continue
            } else {
                print("Have a good one!")
                gameOn = false
            }

    }