How to calculate string in text field by Xcode 8.3.3 - xcode

Question

I want a solution in my problem.
I have text field in Xcode and I wanna Xcode calculate string thats user input as:
var x = 1
var y = 2
like this
I wanna if the user input xy inside text field, the Xcode calculate like: 1+2
import UIKit
class ViewController: UIViewController, UITextFieldDelegate {
#IBOutlet var label1: UILabel!
#IBOutlet var label2: UILabel!
#IBOutlet var label3: UILabel!
#IBOutlet var label4: UILabel!
#IBOutlet var tex1: UITextField!
#IBOutlet var tex2: UITextField!
override function viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
tex1.delegate = self
tex2.delegate = self
}
override function didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
function textFieldShouldReturn(_ textField: UITextField) -> Bool{
tex1.resignFirstResponder()
tex2.resignFirstResponder()
return true
}
#IBAction function close(_ sender: UIButton) {
tex1.resignFirstResponder()
tex2.resignFirstResponder()
}
#IBAction function pushAction(_ sender: UIButton) {
label4.text = String(Int(tex1.text)+Int(tex2.text))
}
}

Answer 1

var temp = 0
var prevCount = -1
func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
var txtAfterUpdate:NSString = textField.text! as NSString
txtAfterUpdate = txtAfterUpdate.replacingCharacters(in: range, with: string).trimmingCharacters(in: CharacterSet.whitespacesAndNewlines) as NSString
let newString:String! = String(txtAfterUpdate)
if(prevCount > newString.characters.count - 1){
if(newString.characters.count - 1 != -1){
self.enterAmount = self.enterAmount - Double(textField.text![(textField.text?.characters.count)! - 1])!
}else{
self.enterAmount = 0
}
}else{
self.enterAmount = Double(newString[newString.characters.count - 1])! + self.enterAmount
}
print("YOUR TOTAL \(self.enterAmount)")
prevCount = newString.characters.count - 1
return true
}
extension String{
subscript(i: Int) -> String {
guard i >= 0 && i < characters.count else { return "" }
return String(self[index(startIndex, offsetBy: i)])
}
subscript(range: Range<Int>) -> String {
let lowerIndex = index(startIndex, offsetBy: max(0,range.lowerBound), limitedBy: endIndex) ?? endIndex
return substring(with: lowerIndex..<(index(lowerIndex, offsetBy: range.upperBound - range.lowerBound, limitedBy: endIndex) ?? endIndex))
}
subscript(range: ClosedRange<Int>) -> String {
let lowerIndex = index(startIndex, offsetBy: max(0,range.lowerBound), limitedBy: endIndex) ?? endIndex
return substring(with: lowerIndex..<(index(lowerIndex, offsetBy: range.upperBound - range.lowerBound + 1, limitedBy: endIndex) ?? endIndex))
}
}

Answer 2

you can use like this
label4.text = "\(((tex1.text?.characters.count)! + (tex2.text?.characters.count)!))"