tryParse method

int? tryParse(
  1. String formattedDateTime,
  2. int start,
  3. int end
)

Implementation

int? tryParse(String formattedDateTime, int start, int end) {
  var result = 0;
  for (var i = start; i < end; i++) {
    var digit = formattedDateTime.codeUnitAt(i) ^ 0x30;
    if (digit <= 9) {
      result = result * 10 + digit;
    } else {
      return null;
    }
  }
  return result;
}