Swift - Automatic Caluclation - swift

Question

I am currently building a calculator app with swift.
I want the calculation to be automatic instead of me pressing = button.
EQLabel is where i want the calculation to be
and inputLabel is where the user can see there equation for example 1 + 5
Below is my calculator code.
// Start of Calculator
#IBOutlet weak var EQLabel: UITextField!
#IBOutlet weak var inputLabel: UITextField!
var numberOnScreen = 0;
var previousNumber = 0;
var performingMath = false
var operation = 0;
#IBAction func numbers(_ sender: UIButton) {
if performingMath == true {
inputLabel.text = String(sender.tag-1)
numberOnScreen = Int(Double(inputLabel.text!)!)
performingMath = false
}
else {
inputLabel.text = String(sender.tag-1)
numberOnScreen = Int(Double(inputLabel.text!)!)
}
}
#IBAction func multiButtons(_ sender: UIButton) {
if inputLabel.text != "" && sender.tag != 15 {
previousNumber = Int(Double(inputLabel.text!)!)
// Plus
if sender.tag == 11 {
inputLabel.text! = "+"
}
// Times
if sender.tag == 12 {
inputLabel.text = "x"
}
// Minus
if sender.tag == 13 {
inputLabel.text = "-"
}
// Divide
if sender.tag == 14 {
inputLabel.text = "/"
}
operation = sender.tag
performingMath = true
}
else if sender.tag == 15 {
if operation == 11 {
EQLabel.text = String(previousNumber + numberOnScreen)
}
if operation == 12 {
EQLabel.text = String(previousNumber * numberOnScreen)
}
if operation == 13 {
EQLabel.text = String(previousNumber - numberOnScreen)
}
if operation == 14 {
EQLabel.text = String(previousNumber / numberOnScreen)
}
}
}

Answer 1

Hope this helps. Should do exactly what you want.
override func viewDidLoad() {
yourTextField.addTarget(self, action: #selector(self.calculateTotal(_:)), forControlEvents: UIControlEvents.EditingChanged)
}
func calculateTotal() {
let totalInt = Int(firstTextField.text!) + Int(secondTextField.text!)
totalLabel.text = String(totalInt)
}
Do let me know if you have any doubts.

Answer 2

Try using addTarget on your button. But your calculator needs to know when you have finished typing in the second number, unless you are only using numbers of a certain length?. If you want it to update the answer as you type id go with something like.
inputLabel.addTarget(self, action: #selector(yourCaculateMethod), for: .editingChanged)
then have your equalsLabel.text equal the result. this will update it as you go.
Id think about naming your inputLabel to inputTextField too as its a little missleading