formatCardNumber static method

String formatCardNumber(
  1. String cardNumber
)

Format card number for display

Implementation

static String formatCardNumber(String cardNumber) {
  final digits = cardNumber.replaceAll(RegExp(r'[^\d]'), '');
  final buffer = StringBuffer();

  for (int i = 0; i < digits.length; i++) {
    if (i > 0 && i % 4 == 0) {
      buffer.write(' ');
    }
    buffer.write(digits[i]);
  }

  return buffer.toString();
}