Dynamically format a number to have commas in a UITextField - ios

Question

How to format the price textfield text as a currency format like 234,345,567 and also I need to restrict the decimal points to not more than 2 and also to append $ symbol when user starts typing.
for example : $234,345,678.25
like this I want to add comma between 3numbers when they type the amount in textfield
func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
if ((string == "0" || string == "") && (txtFldPostalCode.text! as NSString).range(of: ".").location < range.location) {
return true
}
let cs = NSCharacterSet(charactersIn: "0123456789.").inverted
let filtered = string.components(separatedBy: cs)
let component = filtered.joined(separator: "")
let isNumeric = string == component
if isNumeric {
let formatter = NumberFormatter()
formatter.numberStyle = .decimal
formatter.maximumFractionDigits = 8
let newString = (textField.text! as NSString).replacingCharacters(in: range, with: string)
let numberWithOutCommas = newString.replacingOccurrences(of: ",", with: "")
let number = formatter.number(from: numberWithOutCommas)
if number != nil {
var formattedString = formatter.string(from: number!)
if string == "." && range.location == textField.text?.length {
formattedString = formattedString?.appending(".")
}
textField.text = formattedString
} else {
textField.text = nil
}
}
return false
}

Answer 1

For Swift 3. Input currency format on a text field (from right to left)
#IBOutlet weak var textfield: UITextField!
override func viewDidLoad() {
super.viewDidLoad()
textfield.addTarget(self, action: #selector(myTextFieldDidChange), for: .editingChanged)
// Do any additional setup after loading the view.
}
#objc func myTextFieldDidChange(_ textField: UITextField) {
if let amountString = textField.text?.currencyInputFormatting() {
textField.text = amountString
}
}
}
extension String {
// formatting text for currency textField
func currencyInputFormatting() -> String {
var number: NSNumber!
let formatter = NumberFormatter()
formatter.numberStyle = .currencyAccounting
formatter.currencySymbol = "$"
formatter.maximumFractionDigits = 2
formatter.minimumFractionDigits = 2
var amountWithPrefix = self
let regex = try! NSRegularExpression(pattern: "[^0-9]", options: .caseInsensitive)
amountWithPrefix = regex.stringByReplacingMatches(in: amountWithPrefix, options: NSRegularExpression.MatchingOptions(rawValue: 0), range: NSMakeRange(0, self.characters.count), withTemplate: "")
let double = (amountWithPrefix as NSString).doubleValue
number = NSNumber(value: (double / 100))
guard number != 0 as NSNumber else {
return ""
}
return formatter.string(from: number)!
}
Hope this is helpful...