I have json response which comes in different languages and I want to compare day; when I choose language Turkish it gets a response like:
sunday = {
day = Pazar;
timings = (
{
endTime = "23:59:00";
id = 100000174;
startTime = "11:58:00";
}
);
};
wednesday = {
day = "\U00e7ar\U015famba";
timings = (
{
endTime = "22:00:00";
id = 100000177;
startTime = "13:00:00";
}
);
};
I want to compare them the following way:
if(day.lowercased() == “\U00e7ar\U015famba”) {
//get Wednesday day
//this condition work in Sunday Dictionary
}
But It shows me error “Invalid escape sequence” and “closure expression is unused” Please see this image.
In Swift, hexadecimal value after the \u escape sequence needs to be enclosed in braces (with the \u as lowercase):
"\u{00e7}ar\u{015f}amba"
That's the reason for the error you're getting.
However, if you're comparing with the values returned from your JSON, which don't follow this format, you'll need to double-escape the \U to compare them as plain strings:
if day.lowercased() == "\\U00e7ar\\U015famba" {
...
}
Related
I guess it is not possible to parse a date in "MMddyy" format in dart.
void main() {
String strcandidate = "031623";
String format = "MMddyy";
var originalFormat = DateFormat(format).parse(strcandidate);
}
Output:
Uncaught Error: FormatException: Trying to read dd from 031623 at position 6
The following works fine when parsing a date in "MM-dd-yy" format.
void main() {
String strcandidate = "03-16-23";
String format = "MM-dd-yy";
var originalFormat = DateFormat(format).parse(strcandidate);
}
In the problem, the input date string can be in any format e.g ['yyyy-MM-dd', 'MMM'-yyyy, 'MM/dd/yy']. I am parsing the input string for these formats in a loop as follows.
dateFormatsList = ['yyyy-MM-dd', 'MMM'-yyyy, 'MM/dd/yy'];
for (String format in dateFormatsList ) {
try {
originalFormat = DateFormat(format).parse(strcandidate);
dateFound = true;
} catch (e) {}
}
Adding 'MMddyy' to dateFormatsList is not going to work.
But regular expression be used to parse this format.
However if all formats are parsed using parse method and one additional format is parsed using regular expression, then the code is not that neat, and cluttered.
To write as much neat and efficient code as possible, if you want, you can share your insights about any possibility for making it efficient and clean while incorporating 'MMddyy'format. Tysm!
See How do I convert a date/time string to a DateTime object in Dart? for how to parse various date/time strings to DateTime objects.
If you need to mix approaches, you can provide a unified interface. Instead of using a List<String> for your list of formats, you can use a List<DateTime Function(String)>:
import 'package:intl/intl.dart';
/// Parses a [DateTime] from [dateTimeString] using a [RegExp].
///
/// [re] must have named groups with names `year`, `month`, and `day`.
DateTime parseDateFromRegExp(RegExp re, String dateTimeString) {
var match = re.firstMatch(dateTimeString);
if (match == null) {
throw FormatException('Failed to parse: $dateTimeString');
}
var year = match.namedGroup('year');
var month = match.namedGroup('month');
var day = match.namedGroup('day');
if (year == null || month == null || day == null) {
throw ArgumentError('Regular expression is malformed');
}
// In case we're parsing a two-digit year format, instead of
// parsing the strings ourselves, reparse it with [DateFormat] so that it can
// apply its -80/+20 rule.
//
// [DateFormat.parse] doesn't work without separators, which is why we
// can't use directly on the original string. See:
// https://github.com/dart-lang/intl/issues/210
return DateFormat('yy-MM-dd').parse('$year-$month-$day');
}
typedef DateParser = DateTime Function(String);
DateParser dateParserFromRegExp(String rePattern) =>
(string) => parseDateFromRegExp(RegExp(rePattern), string);
var parserList = [
DateFormat('yyyy-MM-dd').parse,
DateFormat('MMM-yyyy').parse,
DateFormat('MM/dd/yy').parse,
dateParserFromRegExp(
r'^(?<month>\d{2})(?<day>\d{2})(?<year>\d{4})$',
)
];
void main() {
var strcandidate = '12311776';
DateTime? originalFormat;
for (var tryParse in parserList) {
try {
originalFormat = tryParse(strcandidate);
break;
} on Exception {
// Try the next format.
}
}
print(originalFormat);
}
I think it's a bit hacky but what about use a regular expression (RegExp) to parse the date divider and then replace it with just ""?
void main() {
String strcandidate = "031623";
String strYear = strcandidate.substring(4);
//Taken 20 as the year like 2023 as year is in 2 digits
String _newDateTime = '20' + strYear + strcandidate.substring(0, 4);
var _originalFormat = DateTime.parse(_newDateTime);
print(_originalFormat);
}
add the intl to yaml then write this code:
import 'package:intl/intl.dart';
void main() {
var strcandidate = DateTime(2023, 3, 16);
String format = "MMddyy";
var originalFormat = DateFormat(format).format(strcandidate);
print(originalFormat);
}
I have a String date in format Month-Day-4DigitYear that I want to convert to DateTime in Flutter. I'm a novice coder, and I'm struggling to understand the api.flutter.dev Parse method example.
Below is the example. I just have a few issues. Android Studio throws multiple errors when I just create a class and put in this function. I think I understand the non-nullable issue, so I delete the ! and ? marks everywhere.
My issues are: what are _parseFormat, _brokenDownDateToValue, _withValue ?
All give errors and just declaring the first two and deleting the _withValue doesn't seem to do the trick, although removes all errors. It's like they've left out a key portion that I'm missing or there is a package I need to import the neither I nor Android Studio knows about. Can anyone decrypt this? I get very frustrated with flutter's documentation, as it always seems to give 80% of required info, assuming you already are clairvoyant on all other topics except this single one they are discussing. Gotta be a pro before reading the manual.
// TODO(lrn): restrict incorrect values like 2003-02-29T50:70:80.
// Or not, that may be a breaking change.
static DateTime parse(String formattedString) {
var re = _parseFormat;
Match? match = re.firstMatch(formattedString);
if (match != null) {
int parseIntOrZero(String? matched) {
if (matched == null) return 0;
return int.parse(matched);
}
// Parses fractional second digits of '.(\d+)' into the combined
// microseconds. We only use the first 6 digits because of DateTime
// precision of 999 milliseconds and 999 microseconds.
int parseMilliAndMicroseconds(String? matched) {
if (matched == null) return 0;
int length = matched.length;
assert(length >= 1);
int result = 0;
for (int i = 0; i < 6; i++) {
result *= 10;
if (i < matched.length) {
result += matched.codeUnitAt(i) ^ 0x30;
}
}
return result;
}
int years = int.parse(match[1]!);
int month = int.parse(match[2]!);
int day = int.parse(match[3]!);
int hour = parseIntOrZero(match[4]);
int minute = parseIntOrZero(match[5]);
int second = parseIntOrZero(match[6]);
int milliAndMicroseconds = parseMilliAndMicroseconds(match[7]);
int millisecond =
milliAndMicroseconds ~/ Duration.microsecondsPerMillisecond;
int microsecond = milliAndMicroseconds
.remainder(Duration.microsecondsPerMillisecond) as int;
bool isUtc = false;
if (match[8] != null) {
// timezone part
isUtc = true;
String? tzSign = match[9];
if (tzSign != null) {
// timezone other than 'Z' and 'z'.
int sign = (tzSign == '-') ? -1 : 1;
int hourDifference = int.parse(match[10]!);
int minuteDifference = parseIntOrZero(match[11]);
minuteDifference += 60 * hourDifference;
minute -= sign * minuteDifference;
}
}
int? value = _brokenDownDateToValue(years, month, day, hour, minute,
second, millisecond, microsecond, isUtc);
if (value == null) {
throw FormatException("Time out of range", formattedString);
}
return DateTime._withValue(value, isUtc: isUtc);
} else {
throw FormatException("Invalid date format", formattedString);
}
}
My issues are: what are _parseFormat, _brokenDownDateToValue, _withValue ?
These are objects or functions declared elsewhere in the lib which are private (the _ as the first character declares objects and functions as private) and therefore not shown in the documentation.
_parseFormat seems to be a regular expression.
_brokenDownDateToValue seems to be a function.
_withValue is a named constructor.
I think what you want to use is the following if you want to parse your date String to a DateTime object.
var date = "11-28-2020"; // Month-Day-4DigitYear
var dateTime = DateTime.parse(date.split('-').reversed.join());
See https://api.flutter.dev/flutter/dart-core/DateTime/parse.html for the accepted strings to be parsed.
I did find the full code example here.
It didn't use the name _parseFormat, instead just RegExp? And has _withValue and _brokenDownDateToValue declarations.
As I see it, there isn't a proper way to decode their example. The example is insufficient. A dictionary should not create definitions using words that can't be found elsewhere in the dictionary.
I have to compare two dates.
The first one I get from the TMaskEdit component with the DD-MM-YYYY mask.
I get the second date from the Date() function.
I tried something like this:
String MaskEditDate = me3->Text.Trim();
String ActualDate = Date().FormatString("DD-MM-YYYY");
TDate TDMaskEditDate = StrToDate(MaskEditDate);
TDate TDActualDate = StrToDate(ActualDate);
if (TDMaskEditDate > TDActualDate)
{
ShowMessage("TDMaskEditDate > TDActualDate");
}
if (TDMaskEditDate == TDActualDate)
{
ShowMessage("TDMaskEditDate == TDActualDate");
}
if (TDMaskEditDate < TDActualDate)
{
ShowMessage("TDMaskEditDate < TDActualDate");
}
But, when I try to convert a string to a date, I get an error message like '2000-01-01' is not a valid date and I do not know why.
StrToDate() parses the input string according to the format specified by the global ShortDateFormat and DateSeparator formatting variables in the SysUtils unit. Those variables are initialized at app startup to your OS's current user locale. This is documented behavior in BCB's help file.
So clearly, one of the input strings you pass to StrToDate() does not match the format that your OS is using for dates, which is why you get the error.
To do what you are attempting, you would have to update those formatting variables to match the format used by your input (as the overloaded version of StrToDate() that takes a TFormatSettings as input did not exist yet in BCB6). And there is absolutely no reason to take a TDate from Date(), convert it to a String, and then parse it back into a TDate, that is just redundant.
Try this instead:
String MaskEditDate = me3->Text.Trim();
TDate TDActualDate = Date();
String oldShortDateFormat = ShortDateFormat;
Char oldDateSeparator = DateSeparator;
ShortDateFormat = "DD-MM-YYYY";
DateSeparator = '-';
TDate TDMaskEditDate = StrToDate(MaskEditDate);
ShortDateFormat = oldShortDateFormat;
DateSeparator = oldDateSeparator;
However, you really should not be using a T(Mask)Edit for date input anyway. A much safer option is to use the TDateTimePicker control instead. Set its Kind property to dtkDate and then read its Date property when needed. There is no need to process your date values using strings at all:
TDate TDDateTimePickerDate = DateTimePicker1->Date;
TDate TDActualDate = Date();
if (TDDateTimePickerDate > TDActualDate)
{
ShowMessage("TDDateTimePickerDate > TDActualDate");
}
else if (TDDateTimePickerDate == TDActualDate)
{
ShowMessage("TDDateTimePickerDate == TDActualDate");
}
else //if (TDDateTimePickerDate < TDActualDate)
{
ShowMessage("TDDateTimePickerDate < TDActualDate");
}
Alternatively:
#include <DateUtils.hpp>
TDate TDDateTimePickerDate = DateTimePicker1->Date;
TDate TDActualDate = Date();
switch (CompareDate(TDDateTimePickerDate, TDActualDate))
{
case GreaterThanValue:
ShowMessage("TDDateTimePickerDate > TDActualDate");
break;
case EqualsValue:
ShowMessage("TDDateTimePickerDate == TDActualDate");
break;
case LessThanValue:
ShowMessage("TDDateTimePickerDate < TDActualDate");
break;
}
I have a string (HTML in this example case) which contains the same pattern for displaying the results of sports games. So, the HTML tags are known, but the values for each game are not.
In Perl, we can do this:
if ( $content =~ /\<\/a\>\<br\>(\d+)\<\/span\>\<br\>(\d+)\-(\d+).+\<\/a\>\<br\>(\d+)\<\/span\>\<br\>(\d+)\-(\d+)/) {
$visitingTeamScore = $1; // $1 is the 1st matched digit
$visitingTeamWins = $2; // $2 is the 2nd matched digit
$visitingTeamLosses = $3; // Etc
$homeTeamScore = $4;
$homeTeamWins = $5;
$homeTeamLosses = $6;
}
which returns the digits inside the parentheses, in this case 6 total integers of varying digit lengths. We can then assign those matches to variables.
From an answer in this question: Swift Get string between 2 strings in a string, I have the following Swift code:
extension String {
func sliceFrom(start: String, to: String) -> String? {
return (rangeOfString(start)?.endIndex).flatMap { sInd in
(rangeOfString(to, range: sInd..<endIndex)?.startIndex).map { eInd in
substringWithRange(sInd..<eInd)
}
}
}
}
let firstMatch = content?.sliceFrom("</a><br>", to: "</span>") // The first integer in the string
The problem comes in when getting the 4th integer which is also between </a\><br> and </span> so the resulting match will be the first digit again.
I can manually count the characters (which itself isn't a perfect science because the digits in each integer can differ) to do something ugly like:
let newRawHTML = content![content!.startIndex.advancedBy(15)...content!.startIndex.advancedBy(5)]
Another possibility is to remove anything matched already from the string, making it shorter for each subsequent search (which I'm not sure how to implement.) What's the way to do this? Is there any way in Swift to "pluck out" the matches?
The code you have shown as a Perl example, uses regular expression.
And in case the pattern is getting a little bit complex, you'd better use NSRegularExpression directly.
let pattern = "</a><br>(\\d+)</span><br>(\\d+)-(\\d+).+</a><br>(\\d+)</span><br>(\\d+)-(\\d+)"
let regex = try! NSRegularExpression(pattern: pattern, options: [])
if let match = regex.firstMatchInString(content, options: [], range: NSRange(0..<content.utf16.count)) {
let visitingTeamScore = (content as NSString).substringWithRange(match.rangeAtIndex(1))
let visitingTeamWins = (content as NSString).substringWithRange(match.rangeAtIndex(2))
let visitingTeamLosses = (content as NSString).substringWithRange(match.rangeAtIndex(3))
let homeTeamScore = (content as NSString).substringWithRange(match.rangeAtIndex(4))
let homeTeamWins = (content as NSString).substringWithRange(match.rangeAtIndex(5))
let homeTeamLosses = (content as NSString).substringWithRange(match.rangeAtIndex(6))
//...use the values
}
I have been given some file name which can be like
<filename>YYYYMMDD<fileextension>
some valid file names that will satisfy the above pattern are as under
xxx20100326.xls,
xxx2v20100326.csv,
x_20100326.xls,
xy2z_abc_20100326_xyz.csv,
abc.xyz.20100326.doc,
ab2.v.20100326.doc,
abc.v.20100326_xyz.xls
In what ever be the above defined case, I need to pick up the dates only. So for all the cases, the output will be 20100326.
I am trying to achieve the same but no luck.
Here is what I have done so far
string testdata = "x2v20100326.csv";
string strYYYY = #"\d{4}";
string strMM = #"(1[0-2]|0[1-9])";
string strDD = #"(3[0-1]|[1-2][0-9]|0[1-9])";
string regExPattern = #"\A" + strYYYY + strMM + strDD + #"\Z";
Regex regex = new Regex(regExPattern);
Match match = regex.Match(testdata);
if (match.Success)
{
string result = match.Groups[0].Value;
}
I am using c#3.0 and dotnet framework 3.5
Please help. It is very urgent
Thanks in advance.
Try this:
DateTime result = DateTime.MinValue;
System.Globalization.CultureInfo provider = System.Globalization.CultureInfo.InvariantCulture;
var testString = "x2v20100326.csv";
var format = "yyyyMMdd";
try
{
for (int i = 0; i < testString.Length - format.Length; i++)
{
if (DateTime.TryParseExact(testString.Substring(i, format.Length), format, provider, System.Globalization.DateTimeStyles.None, out result))
{
Console.WriteLine("{0} converts to {1}.", testString, result.ToString());
break;
}
}
}
catch (FormatException)
{
Console.WriteLine("{0} is not in the correct format.", testString);
}
This one fetches the last date in the string.
var re = new Regex("(?<date>[0-9]{8})");
var test = "asdf_wef_20100615_sdf.csv";
var datevalue = re.Match(test).Groups["date"].Value;
Console.WriteLine(datevalue); // prints 20100615
Characters \A and \Z - begin and end of the string respectivly.
I think you need pattern like:
string regExPattern = #"\A.*(?<FullDate>" + strYYYY + strMM + strDD + #").*\..*\Z";
".*" - any symbols at the begin
".*\..*" - any symbols before the dot, dot and any symbols after dot
And get a full date:
match.Groups["FullDate"]
You may need to group things in your month and day expressions:
((1[0-2])|(0[1-9))
((3[0-1])|([1-2][0-9])|(0[1-9]))