My first app

import UIKit class CalculatorViewController: UIViewController { @IBOutlet weak var decimalButton: UIButton! @IBOutlet weak var subtractButton: UIButton! @IBOutlet weak var divideButton: UIButton! @IBOutlet weak var addButton: UIButton! @IBOutlet weak var multiplyButton: UIButton! @IBOutlet weak var equalsButton: UIButton! @IBOutlet weak var outputLabel: UILabel! @IBOutlet weak var clearButton: UIButton! @IBOutlet weak var previousAnswerLabel: UILabel! @IBOutlet weak var previousAnswerTitle: UILabel! @IBOutlet weak var copyButton: UIButton! var brain: CalculatorBrain? let xYValue = 0.75 let durationTime = 0.15 override func viewDidLoad() { super.viewDidLoad() previousAnswerLabel.text = nil previousAnswerTitle.text = nil brain = CalculatorBrain() } // MARK: - Action Handlers @IBAction func operandTapped(_ sender: UIButton) { UIButton.animate(withDuration: durationTime, animations: { sender.transform = CGAffineTransform(scaleX: CGFloat(self.xYValue), y: CGFloat(self.xYValue)) }, completion: { finish in UIButton.animate(withDuration: self.durationTime, animations: { sender.transform = CGAffineTransform.identity }) }) // Takes in the value of the operand tapped if let operandTapped = sender.titleLabel?.text { let buttonDoesntContainDecimal = !operandTapped.contains(".") let buttonContainsDecimalWithNoCurrentDecimal = operandTapped.contains(".") && !(outputLabel.text?.contains(".") ?? false) if buttonDoesntContainDecimal || buttonContainsDecimalWithNoCurrentDecimal { outputLabel.text = brain?.addOperandDigit(operandTapped) } } } @IBAction func operatorTapped(_ sender: UIButton) { UIButton.animate(withDuration: durationTime, animations: { sender.transform = CGAffineTransform(scaleX: CGFloat(self.xYValue), y: CGFloat(self.xYValue))}, completion: { finish in UIButton.animate(withDuration: self.durationTime, animations: { sender.transform = CGAffineTransform.identity }) }) // Takes in the value of the operator tapped if let operatorValueTapped = sender.titleLabel?.text { brain?.setOperator(operatorValueTapped) } } @IBAction func equalTapped(_ sender: UIButton) { UIButton.animate(withDuration: durationTime, animations: { sender.transform = CGAffineTransform(scaleX: CGFloat(self.xYValue), y: CGFloat(self.xYValue)) }, completion: { finish in UIButton.animate(withDuration: self.durationTime, animations: { sender.transform = CGAffineTransform.identity }) }) // Calculates the answer and sets it to the value 'answer' if let answer = brain!.calculateIfPossible() { copyButton.setTitleColor(.green, for: .normal) previousAnswerLabel.text = answer previousAnswerTitle.text = "Previous Answer" outputLabel.text = answer } } @IBAction func clearTapped(_ sender: UIButton) { UIButton.animate(withDuration: durationTime, animations: { sender.transform = CGAffineTransform(scaleX: CGFloat(self.xYValue), y: CGFloat(self.xYValue)) }, completion: { finish in UIButton.animate(withDuration: self.durationTime, animations: { sender.transform = CGAffineTransform.identity }) }) // Clears the calculation when tapped if outputLabel.text == "0" { clearTransaction() copyButton.setTitleColor(.black, for: .normal) previousAnswerTitle.text = nil previousAnswerLabel.text = nil } clearTransaction() outputLabel.text = "0" } // MARK: - Private private func clearTransaction() { // Clear calculation function brain = CalculatorBrain() } @IBAction func posNegButtonTapped(_ sender: UIButton) { UIButton.animate(withDuration: durationTime, animations: { sender.transform = CGAffineTransform(scaleX: CGFloat(self.xYValue), y: CGFloat(self.xYValue)) }, completion: { finish in UIButton.animate(withDuration: self.durationTime, animations: { sender.transform = CGAffineTransform.identity }) }) // Turns number negative or positive if var posNegNumber = Double(outputLabel.text ?? "") { posNegNumber = posNegNumber * -1.0 outputLabel.text = String(posNegNumber) brain?.operand1String = String(posNegNumber) } } @IBAction func percentButtonTapped(_ sender: UIButton) { UIButton.animate(withDuration: durationTime, animations: { sender.transform = CGAffineTransform(scaleX: CGFloat(self.xYValue), y: CGFloat(self.xYValue)) }, completion: { finish in UIButton.animate(withDuration: self.durationTime, animations: { sender.transform = CGAffineTransform.identity }) }) // Divides by 100.0 (Double) to return the percentageNumber if var percentageNumber = Double(outputLabel.text ?? "") { percentageNumber = percentageNumber / 100.0 outputLabel.text = String(percentageNumber) brain?.operand1String = String(percentageNumber) } } @IBAction func subtractButtonPressed(_ sender: Any) { // Set color for button pressed subtractButton.backgroundColor = .white subtractButton.setTitleColor(.black, for: .normal) // Set default colors back divideButton.backgroundColor = .green divideButton.setTitleColor(.white, for: .normal) multiplyButton.backgroundColor = .green multiplyButton.setTitleColor(.white, for: .normal) addButton.backgroundColor = .green addButton.setTitleColor(.white, for: .normal) equalsButton.backgroundColor = .green equalsButton.setTitleColor(.white, for: .normal) } @IBAction func divideButtonPressed(_ sender: Any) { // Set color for button pressed divideButton.backgroundColor = .white divideButton.setTitleColor(.black, for: .normal) // Set default colors back subtractButton.backgroundColor = .green subtractButton.setTitleColor(.white, for: .normal) multiplyButton.backgroundColor = .green multiplyButton.setTitleColor(.white, for: .normal) addButton.backgroundColor = .green addButton.setTitleColor(.white, for: .normal) equalsButton.backgroundColor = .green equalsButton.setTitleColor(.white, for: .normal) } @IBAction func multiplyButtonPressed(_ sender: Any) { // Set color for button pressed multiplyButton.backgroundColor = .white multiplyButton.setTitleColor(.black, for: .normal) // Set default colors back subtractButton.backgroundColor = .green subtractButton.setTitleColor(.white, for: .normal) divideButton.backgroundColor = .green divideButton.setTitleColor(.white, for: .normal) addButton.backgroundColor = .green addButton.setTitleColor(.white, for: .normal) equalsButton.backgroundColor = .green equalsButton.setTitleColor(.white, for: .normal) } @IBAction func addButtonPressed(_ sender: Any) { // Set color for button pressed addButton.backgroundColor = .white addButton.setTitleColor(.black, for: .normal) // Set default colors back subtractButton.backgroundColor = .green subtractButton.setTitleColor(.white, for: .normal) multiplyButton.backgroundColor = .green multiplyButton.setTitleColor(.white, for: .normal) divideButton.backgroundColor = .green divideButton.setTitleColor(.white, for: .normal) equalsButton.backgroundColor = .green equalsButton.setTitleColor(.white, for: .normal) } @IBAction func equalButtonPressed(_ sender: Any) { // Set color for button pressed equalsButton.backgroundColor = .white equalsButton.setTitleColor(.black, for: .normal) // Set default colors back subtractButton.backgroundColor = .green subtractButton.setTitleColor(.white, for: .normal) multiplyButton.backgroundColor = .green multiplyButton.setTitleColor(.white, for: .normal) addButton.backgroundColor = .green addButton.setTitleColor(.white, for: .normal) divideButton.backgroundColor = .green divideButton.setTitleColor(.white, for: .normal) } @IBAction func clearButtonPressed(_ sender: Any) { // Default all colors when clear button pressed equalsButton.backgroundColor = .green equalsButton.setTitleColor(.white, for: .normal) subtractButton.backgroundColor = .green subtractButton.setTitleColor(.white, for: .normal) multiplyButton.backgroundColor = .green multiplyButton.setTitleColor(.white, for: .normal) addButton.backgroundColor = .green addButton.setTitleColor(.white, for: .normal) divideButton.backgroundColor = .green divideButton.setTitleColor(.white, for: .normal) } @IBAction func copyButtonPressed(_ sender: Any) { outputLabel.text = previousAnswerLabel.text brain?.operand1String = previousAnswerLabel.text ?? "" } } 

import Foundation enum OperatorType: String { case addition = "+" case subtraction = "−" case multiplication = "×" case division = "÷" } class CalculatorBrain { var operand1String = "" var operand2String = "" var operatorType: OperatorType? func addOperandDigit(_ digit: String) -> String { // Adds operand digit if nil if operatorType != nil { operand2String.append(digit) return operand2String } else { operand1String.append(digit) return operand1String } } func setOperator(_ operatorString: String) { // Sets the operator to it's rawValue operatorType = OperatorType(rawValue: operatorString) } func calculateIfPossible() -> String? { // Calculation for .addition, .subtraction, .multiplication, . division // Checking to see if oprand1String or operand2String are empty let numberFormatting = NumberFormatter() numberFormatting.usesGroupingSeparator = true numberFormatting.numberStyle = .decimal numberFormatting.locale = Locale.current if operand1String.isEmpty, operand2String.isEmpty, operatorType == nil { return "0" } else { var finalAnswer: String if let firstOperandNumber = Double(operand1String), let secondOperandNumber = Double(operand2String) { switch operatorType { case .addition? : finalAnswer = String(firstOperandNumber + secondOperandNumber) case .subtraction? : finalAnswer = String(firstOperandNumber - secondOperandNumber) case .multiplication? : finalAnswer = String(firstOperandNumber * secondOperandNumber) case .division? : if secondOperandNumber == 0 { return "Nice try ;)" } else { finalAnswer = String(firstOperandNumber / secondOperandNumber) } default : return nil } } else { return nil } operand1String = finalAnswer operand2String = "" return finalAnswer } } }