description

# toString method Null safety

String toString ()
override

Returns a string representation of this `Duration`.

Returns a string with hours, minutes, seconds, and microseconds, in the following format: `H:MM:SS.mmmmmm`. For example,

    var d = Duration(days: 1, hours: 1, minutes: 33, microseconds: 500);
    d.toString();  // "25:33:00.000500"

    d = Duration(days: 0, hours: 1, minutes: 10, microseconds: 500);
    d.toString();  // "1:10:00.000500"

## Implementation

    String toString() {
      String sixDigits(int n) {
        if (n >= 100000) return "$n";
        if (n >= 10000) return "0$n";
        if (n >= 1000) return "00$n";
        if (n >= 100) return "000$n";
        if (n >= 10) return "0000$n";
        return "00000$n";
      }

      String twoDigits(int n) {
        if (n >= 10) return "$n";
        return "0$n";
      }

      if (inMicroseconds < 0) {
        return "-${-this}";
      }
      String twoDigitMinutes =
          twoDigits(inMinutes.remainder(minutesPerHour) as int);
      String twoDigitSeconds =
          twoDigits(inSeconds.remainder(secondsPerMinute) as int);
      String sixDigitUs =
          sixDigits(inMicroseconds.remainder(microsecondsPerSecond) as int);
      return "$inHours:$twoDigitMinutes:$twoDigitSeconds.$sixDigitUs";
    }