validatecard method

String? validatecard(
  1. String value
)

Implementation

String? validatecard(String value) {
  if (value.isEmpty) return "Enter your Card Number";
  if (value.length < 12) {
    return "Card Number must be 12 Digits";
  }
  // Pattern pattern =
  //     r'^(?=.*?[A-Z])(?=.*?[a-z])(?=.*?[0-9])(?=.*?[!@#\$&*~]).{6,}$';
  // RegExp regex =   RegExp(pattern);
  // if (!regex.hasMatch(value.trim())) {
  //   return "include one capital letter, number and symbol";
  // }
  return null;
}