计算器应用程序不会始终将 multiple-digit 数字和运算 return 归零？

Question

我用的是 Swift 4，数字都是 Int。

所以我做了一个计算class file:

import Foundation
import UIKit

class Calculation {

    var result = Int()
    var operationButton = String()
    var currentNumber = Int()

    func calculator() {

        switch operationButton {
        case "+":
            result = result + currentNumber
        case "-":
            result = result - currentNumber
        case "*":
            result = result * currentNumber
        case "/":
            result = result / currentNumber
        case "=":
            result = currentNumber
        default:
            break
        }

    }

        func textClear() {
            result = 0
            currentNumber = 0
            operationButton = "="
    }

然后我在 UIControllerView 中为 AC 按钮、数字按钮和操作按钮制作了 3 个函数，以直接从按钮标题中获取“0-9”和“-,+,*,/,=”。

    class ViewController: UIViewController {


    @IBOutlet weak var resultTextField: UITextField!

    var calculation = Calculation()

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.

        calculation.operationButton = "="
        resultTextField.text = "\(calculation.result)"
    }


    @IBAction func allClearButtonPressed(_ sender: UIButton) {
        calculation.textClear()
        resultTextField.text = "\(calculation.result)"
    }

    @IBAction func operationButtonPressed(_ sender: UIButton) {

        calculation.operationButton = sender.titleLabel!.text as String!
            calculation.operationButton = sender.titleLabel!.text!
        calculation.calculator()
        resultTextField.text = "\(calculation.result)"
    }

    @IBAction func numberButtonPressed(_ sender: UIButton) {

        calculation.currentNumber = Int((sender.titleLabel?.text)!)!
        let numberInput = String(calculation.currentNumber)
        resultTextField.text = numberInput
    }
}

第一个问题是，每当我尝试输入一个数字（例如 21）时，它只是 returns 2，然后被 1 替换。第二个问题是运算符总是 return 零"resultTextField".

Answer 1

您的 numberButtonPressed 函数读取按钮的文本，替换 currentNumber，然后将其分配给 resultTextField.text。您想要的是将新数字添加到当前号码的功能。在你的 Calculator class.

里面

func pressedDigit(_ digit: Int) {
    currentNumber = currentNumber * 10 + digit
}

然后您可以调用此函数并将currentNumber分配给您的resultTextField。

@IBAction func numberButtonPressed(_ sender: UIButton) {
    guard let digit = sender.titleLabel?.text?.flatMap({ Int(String([=11=])) }) else { return }
    calculation.pressedDigit(value: digit)
    resultTextField.text = "\(calculation.currentNumber)"
}

您还必须在每次计算后重置 currentNumber。

计算器应用程序不会始终将 multiple-digit 数字和运算 return 归零？

Calculator app does not get multiple-digit numbers and operations return zero at all times?

xcode

operations

calculator

swift