#10 猜數字

成品：

code:

```swift

import UIKit

class ViewController: UIViewController {
    
    // IBOutlet連結的元件
    @IBOutlet weak var numberTextField: UITextField!
    @IBOutlet weak var resultLabel: UILabel!
    @IBOutlet weak var guessCountLabel: UILabel!
    @IBOutlet weak var guessButton: UIButton!
    
    // 存放隨機產生的答案
    var answer = Int.random(in: 1...100)
    var guessCount = 0
    var minNumber = 0
    var maxNumber = 100
    
    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view.
    }

    // 猜數字按鈕的動作
    @IBAction func guess(_ sender: Any) {
        let numberText = numberTextField.text!
        let number = Int(numberText)
        
        // 確認輸入的數字是否在範圍內
        if number != nil, number! >= minNumber, number! <= maxNumber {
            let guessNumber = number!
            
            // 猜對了
            if guessNumber == answer {
                resultLabel.text = "答案是\(guessNumber)!\n恭喜你猜對了"
            }
            // 猜錯了，更新範圍
            else if guessNumber < answer {
                minNumber = guessNumber
                resultLabel.text = "範圍\(minNumber)～\(maxNumber)"
                numberTextField.text = ""
                guessCount += 1
            }
            else if guessNumber > answer {
                maxNumber = guessNumber
                resultLabel.text = "範圍\(minNumber)～\(maxNumber)"
                numberTextField.text = ""
                guessCount += 1
            }
            guessCountLabel.text = "剩下 \(6 - guessCount) 次機會"
        }
        // 輸入超出範圍
        if number != nil, number! > maxNumber {
            numberTextField.text = ""
            resultLabel.text = "超出範圍嘍!\n請重新輸入"
        }
        // 輸入非數字
        if number == nil {
            numberTextField.text = ""
            resultLabel.text = "請輸入1~100的數字!!"
        }
        // 猜測次數用完
        if guessCount == 6 {
            numberTextField.text = ""
            guessButton.isEnabled = false
            guessCountLabel.text = "失敗"
            resultLabel.text = "真可惜！！\n答案是\(answer)"
            
        }
        // 縮鍵盤
        view.endEditing(true)
    }
    
    // 重新開始遊戲按鈕的動作
    @IBAction func replay(_ sender: Any) {
        answer = Int.random(in: 1...100)
        guessButton.isEnabled = true
        numberTextField.text = ""
        minNumber = 0
        maxNumber = 100
        guessCount = 0
        resultLabel.text = "請輸入 \(minNumber) ~ \(maxNumber) 的數字"
        guessCountLabel.text = "有 \(6 - guessCount) 次機會"
        
    }
    
}

Github：

GitHub - ZengYahan/guessNumber