Parsing a date string to get the year - c#

I have a string variable that stores a date like "05/11/2010".
How can I parse the string to get only the year?
So I will have another year variable like year = 2010.

You can use the DateTime.Parse Method to parse the string to a DateTime value which has a Year Property:
var result = DateTime.Parse("05/11/2010").Year;
// result == 2010
Depending on the culture settings of the operating system, you may need to provide a CultureInfo:
var result = DateTime.Parse("05/11/2010", new CultureInfo("en-US")).Year;
// result == 2010

This should work for you.
string myDate = "05/11/2010";
DateTime date = Convert.ToDateTime(myDate);
int year = date.Year;

If the date string format is fixed (dd/MM/yyyy), I would like to recommend you using DateTime.ParseExact Method.
The code:
const string dateString = "12/02/2012";
CultureInfo provider = CultureInfo.InvariantCulture;
// Use the invariant culture for the provider parameter,
// because of custom format pattern.
DateTime dateTime = DateTime.ParseExact(dateString, "dd/MM/yyyy", provider);
Console.WriteLine(dateTime);
Also I think it might be a little bit faster than DateTime.Parse Method, because the Parse method tries parsing several representations of date-time string.

you could also used Regex to get the year in the string "05/11/2010"
public string getYear(string str)
{
return (string)Regex.Match(str, #"\d{4}").Value;
}
var result = getYear("05/11/2010");
2010

Variant of dtb that I use:
string Year = DateTime.Parse(DateTime.Now.ToString()).Year.ToString();

Related

DateTime.ParseExact is not doing what i want it to do

When use the .ParseExact() method for the DateTime, i always get the same output as the string i put in. Here is my code:
[Authorize(Roles = "Backoffice, Manager")]
[HttpPost]
public ActionResult FilmShowCreate(FilmShowViewModel newFilmShow)
{
if (ModelState.IsValidField("FilmId") && ModelState.IsValidField("Time"))
{
DateTime unformattedDateTime = newFilmShow.Date.Date + newFilmShow.Time.TimeOfDay;
string dateString = unformattedDateTime.ToString("yyyy-MM-dd HH:mm:ss");
DateTime dbDate = DateTime.ParseExact(dateString, "yyyy-MM-dd HH:mm:ss",
CultureInfo.GetCultureInfo("en-US"), DateTimeStyles.AdjustToUniversal);
FilmShow filmShow = new FilmShow
{
Film = filmRepository.GetFilm(newFilmShow.FilmId),
Cinema = cinemaRepository.GetCinema(newFilmShow.CinemaId),
ThreeDimensional = newFilmShow.ThreeDimensional,
Date = dbDate,
SpecialEvent = newFilmShow.SpecialEvent
};
filmShowsRepository.AddShow(filmShow);
return View("SuccesfullFilmShowCreate");
The string dateString is formatted good, but it is a string and I need to store it in the database as a format DateTime like this "year-month-day hours:minutes:seconds". But for whatever reason the ParseExact doesn't seem to work in my case. The DateTime format i get is "dd-MM-yyyy HH:mm".
It doesn't do what you want because, well, that function isn't supposed to do what you are describing.
ParseExact simply indicates that the input must match the given format in order to be used (and not throw an exception). It is a counterpart to Parse which will accept any valid Date/Time format. It has absolutely no bearing on the future format of any string representation of the DateTime object it creates.
If you want to output it in a given format, pass your format string into ToString before sending that string to the database. Of course, if you are using something like EF, the conversion is done for you and it shouldn't matter.
Example:
string myFormattedDateTime = dbDate.ToString("yyyy-MM-dd HH:mm:ss");
Reading your question more closely, I realize that you seem to think that DateTime has some "stored" format. It does not. DateTime is just a collection of numbers that hold the information required to represent a date and time. The format you are describing only exists in string representations.

Format DateTime object from System time format to required format

My system time is of the format dd-MMM-yy (02-Dec-16). The format I want to convert it to is "yyyy/MM/dd". I've basically been playing around with all the other datetime formats that my system offers and this is the parsing statement I've figured out that works for All of them (except this) -
CultureInfo provider = CultureInfo.InvariantCulture;
string date_format = "yyyy/MM/dd HH:mm:ss tt";
DateTime now_value = DateTime.ParseExact(DateTime.Now.ToString(date_format), date_format, provider);
return now_value.ToString(date_format);
But this doesn't work for the aforementioned dd-MMM-yy format. Can someone please tell me what I am doing wrong here?
(Sidebar -Is there a more efficient way in which I can write this above snippet?)
You don't need to convert DateTime to string and then convert back to DateTime and again back to string, if you have DateTime input just call the ToString with the format as below
string dt =DateTime.Now.ToString("yyyy/MMM/dd", CultureInfo.InvariantCulture);
for your example :
DateTime now_value = DateTime.ParseExact("02-Dec-16", "dd-MMM-yy", System.Globalization.CultureInfo.InvariantCulture);
return now_value.ToString("yyyy/MM/dd");
Try This:
string date_format = "yyyy-MMM-dd";
string date_now = DateTime.Now.ToString(date_format,CultureInfo.CreateSpecificCulture("en-US"));
return date_now;
Even This should also work:
string date_format = "yyyy-MMM-dd";
string date_now = DateTime.Now.ToString(date_format);
return date_now;
I think best way would be to create an extension method for multiple date formats,
var inputDate = "02-Dec-2016";
string[] availaible_input_date_format = { "dd-MMM-yyyy", "dd/MMM/yyyy" }; // add as many formats availible
var date_format = "yyyy/MMM/dd";
DateTime outputDate;
DateTime.TryParseExact(inputDate, availaible_input_date_format, null, DateTimeStyles.None, out outputDate);
Console.WriteLine(outputDate.ToString(date_format));
You can try this:
datetime yourdatetime = new datetime();
string converteddatetime = yourdatetime.toString("yyyy/MM/dd");

Parse String date to specific format

This is a String date:
dob = reader.GetValue(7).ToString();` return like "12/2/2012"
But I want to convert (before passing it) to this format "2012212", I have tried
string newDate = dob.ToString("yyyMMdd")
But I got the following error:
The best overloaded method match for
'string.ToString(System.IFormatProvider)has some invalid arguments
any idea ?
Not Exact way of getting output but it will work.
string dob = "12/2/2012";
string[] d1 = dob.Split('/');
string s = d1[2] + d1[1] + d1[0];
You could use SqlDataReader.GetDateTime if underlying return type is DateTime
Then you just need..
reader.GetDateTime(7).ToString("yyyyMdd");
In case, if it is stored and received as a string then I would suggest converting to DateTime first and then look for specific format.
var date = DateTime.ParseExact(dob, "dd/M/yyyy",CultureInfo.InvariantCulture);
var formattedDate = date.ToString("yyyyMdd");
DateTime.ParseExact(reader.GetValue(7), "dd/M/dd", System.Globalization.CultureInfo.InvariantCulture).ToString("yyyyMMdd");
If you have a date in a String with the format "ddMMyyyy" and want to convert it to "yyyyMMdd" you could do like this:
DateTime dt = DateTime.ParseExact(dob, "ddMMyyyy",
CultureInfo.InvariantCulture);
dt.ToString("yyyyMMdd");
You can try below method to convert string to date.
IFormatProvider culture = new CultureInfo("en-US", true);
dob = DateTime.ParseExact(reader.GetValue(7).ToString(), "dd/MM/yyyy", culture).ToString("yyyyMMdd");
Thank you.

Converting string format to datetime in mm/dd/yyyy

I have to convert string in mm/dd/yyyy format to datetime variable but it should remain in mm/dd/yyyy format.
string strDate = DateTime.Now.ToString("MM/dd/yyyy");
Please help.
You are looking for the DateTime.Parse() method (MSDN Article)
So you can do:
var dateTime = DateTime.Parse("01/01/2001");
Which will give you a DateTime typed object.
If you need to specify which date format you want to use, you would use DateTime.ParseExact (MSDN Article)
Which you would use in a situation like this (Where you are using a British style date format):
string[] formats= { "dd/MM/yyyy" }
var dateTime = DateTime.ParseExact("01/01/2001", formats, new CultureInfo("en-US"), DateTimeStyles.None);
You need an uppercase M for the month part.
string strDate = DateTime.Now.ToString("MM/dd/yyyy");
Lowercase m is for outputting (and parsing) a minute (such as h:mm).
e.g. a full date time string might look like this:
string strDate = DateTime.Now.ToString("MM/dd/yyyy h:mm");
Notice the uppercase/lowercase mM difference.
Also if you will always deal with the same datetime format string, you can make it easier by writing them as C# extension methods.
public static class DateTimeMyFormatExtensions
{
public static string ToMyFormatString(this DateTime dt)
{
return dt.ToString("MM/dd/yyyy");
}
}
public static class StringMyDateTimeFormatExtension
{
public static DateTime ParseMyFormatDateTime(this string s)
{
var culture = System.Globalization.CultureInfo.CurrentCulture;
return DateTime.ParseExact(s, "MM/dd/yyyy", culture);
}
}
EXAMPLE: Translating between DateTime/string
DateTime now = DateTime.Now;
string strNow = now.ToMyFormatString();
DateTime nowAgain = strNow.ParseMyFormatDateTime();
Note that there is NO way to store a custom DateTime format information to use as default as in .NET most string formatting depends on the currently set culture, i.e.
System.Globalization.CultureInfo.CurrentCulture.
The only easy way you can do is to roll a custom extension method.
Also, the other easy way would be to use a different "container" or "wrapper" class for your DateTime, i.e. some special class with explicit operator defined that automatically translates to and from DateTime/string. But that is dangerous territory.
Solution
DateTime.Now.ToString("MM/dd/yyyy", CultureInfo.InvariantCulture)
I did like this
var datetoEnter= DateTime.ParseExact(createdDate, "dd/mm/yyyy", CultureInfo.InvariantCulture);
You can change the format too by doing this
string fecha = DateTime.Now.ToString(format:"dd-MM-yyyy");
// this change the "/" for the "-"
The following works for me.
string strToday = DateTime.Today.ToString("MM/dd/yyyy");

DateTime.Parse with a custom DateTimeFormatInfo throws an exception

Why is this code throwing an exception?
var dateTime = "2012-03-21_15.12";
var format = new DateTimeFormatInfo()
{
FullDateTimePattern = "yyyy-MM-dd-HH_mm.ss"
};
// FormatException: String was not recognized as a valid DateTime.
var parse = DateTime.Parse(dateTime, format);
Your format string and the date string do not match.
You seem to have forgotten either the hours or minutes portion in the date string.
This:
var dateTime = "2012-03-21_15.12";
Should probably look like:
var dateTime = "2012-03-21-15_54.12";
And I suggest using DateTime.ParseExact:
DateTime.ParseExact("2012-03-21-16_15.12",
"yyyy-MM-dd-HH_mm.ss",
CultureInfo.InvariantCulture,
DateTimeStyles.None)
You may want to use DateTime.ParseExact as this will take a datetime format pattern as a parameter.
DateTime.ParseExact

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