Swift で数あてゲーム

guessNumber.swift

import Foundation

class GuessNumber {
  lazy var correctNumber: Int = self.randomNumber()
  var answerNumber: Int = 0
  var answerCount: Int = 1

  init() {
    // Initialize and start game
    printGameGuide()
    startGameLoop()
  }

  func printGameGuide() {
    print("0から999までの範囲にある数字を１つ用意しました。これを当ててください")
    print("(入力に対して、大きな・小さな数字かヒントが出ます)\n")
  }

  func randomNumber() -> Int {
    return {
      // extract 3 digits from random number
      let digit = 1_000
      let num = Double(arc4random()) / Double(digit)
      let cutBeforeDot = Int(num)
      return Int((num - Double(cutBeforeDot)) * Double(digit))
    }()
  }

  func askAnswer() -> Int {
    print("> 数字を入力してください:")
    return Int(readLine(strippingNewline: true)!)!
  }

  func printHint(answerNumber: Int, correctNumber: Int) {
    let difference: Int = answerNumber - correctNumber

    if difference == 0 {
      print("正解!!")
    } else if difference < 0 {
      print(" ?:入力より大きな値です\n")
    } else {
      print(" ?:入力より小さな値です\n")
    }
  }

  func startGameLoop() {
    repeat {
      answerNumber = askAnswer() // Update value
      printHint(answerNumber: answerNumber, correctNumber: correctNumber)
      print("---------------------------")
      if answerNumber != correctNumber { answerCount += 1 }
    } while answerNumber != correctNumber
    print("(", answerCount, "回で正解しました！)")
  }
}

let guessNumber = GuessNumber()