format method

String format(String format)

Formats the DateTime object as a string based on the provided format.

Supported format tokens:

• 'dd': Day of the month (01-31)
• 'MM': Month (01-12)
• 'MMM': Short month name (Jan-Dec)
• 'MMMM': Full month name (January-December)
• 'yyyy': Year
• 'HH': Hour (00-23)
• 'hh': Hour (01-12)
• 'mm': Minute (00-59)
• 'ss': Second (00-59)
• 'a': AM/PM marker
• 'EEE': Short day name (Mon-Sun)
• 'EEEE': Full day name (Monday-Sunday)

Example usage: DateTime now = DateTime.now(); String formattedDate = now.format('dd/MM/yyyy');

Implementation

String format(String format) {
  final Map<String, String> shortMonths = {
    '01': 'Jan',
    '02': 'Feb',
    '03': 'Mar',
    '04': 'Apr',
    '05': 'May',
    '06': 'Jun',
    '07': 'Jul',
    '08': 'Aug',
    '09': 'Sep',
    '10': 'Oct',
    '11': 'Nov',
    '12': 'Dec'
  };

  final Map<String, String> fullMonths = {
    '01': 'January',
    '02': 'February',
    '03': 'March',
    '04': 'April',
    '05': 'May',
    '06': 'June',
    '07': 'July',
    '08': 'August',
    '09': 'September',
    '10': 'October',
    '11': 'November',
    '12': 'December'
  };

  final Map<String, String> shortDays = {
    '1': 'Mon',
    '2': 'Tue',
    '3': 'Wed',
    '4': 'Thu',
    '5': 'Fri',
    '6': 'Sat',
    '7': 'Sun'
  };

  final Map<String, String> fullDays = {
    '1': 'Monday',
    '2': 'Tuesday',
    '3': 'Wednesday',
    '4': 'Thursday',
    '5': 'Friday',
    '6': 'Saturday',
    '7': 'Sunday'
  };

  return format.replaceAllMapped(
    RegExp(r'(dd|MM|MMM|MMMM|yyyy|HH|hh|mm|ss|a|EEE|EEEE|[^\w])'),
    (Match m) {
      switch (m.group(0)) {
        case 'dd':
          return this.day.toString().padLeft(2, '0');
        case 'MM':
          return this.month.toString().padLeft(2, '0');
        case 'MMM':
          return shortMonths[this.month.toString().padLeft(2, '0')]!;
        case 'MMMM':
          return fullMonths[this.month.toString().padLeft(2, '0')]!;
        case 'yyyy':
          return this.year.toString();
        case 'HH':
          return this.hour.toString().padLeft(2, '0');
        case 'hh':
          int hour = this.hour > 12 ? this.hour - 12 : this.hour;
          return hour.toString().padLeft(2, '0');
        case 'mm':
          return this.minute.toString().padLeft(2, '0');
        case 'ss':
          return this.second.toString().padLeft(2, '0');
        case 'a':
          return this.hour < 12 ? 'AM' : 'PM';
        case 'EEE':
          return shortDays[this.weekday.toString()]!;
        case 'EEEE':
          return fullDays[this.weekday.toString()]!;
        default:
          return m.group(0)!;
      }
    },
  );
}