Dart extension methods

extensionmethod.dart

void main() {
  var now = DateTime.now();
        var nextYear = now.nextYear;
        var lastYear = now.previousYear();

        now.printYYYYMMdd("-");
        nextYear.printYYYYMMdd("/");
        lastYear.printYYYYMMdd(".");

}

extension DateExtensions on DateTime{
  
  printYYYYMMdd(String seperator) {
    var dateString = "${this.year}$seperator${getTwoDigit(this.month)}$seperator${getTwoDigit(this.day)}";
    print(dateString);
  }
  
  String getTwoDigit(int number){
    return (number < 10)? "0$number" :number.toString();
  }
  
  DateTime get  nextYear => this.add(Duration(days:365));
  
  DateTime previousYear() => this.subtract(Duration(days:365));
}