How to parse a month name (string) to an integer for comparison in C#?
C#ParsingIntegerCompareC# Problem Overview
I need to be able to compare some month names I have in an array.
It would be nice if there were some direct way like:
Month.toInt("January") > Month.toInt("May")
My Google searching seems to suggest the only way is to write your own method, but this seems like a common enough problem that I would think it would have been already implemented in .Net, anyone done this before?
C# Solutions
Solution 1 - C#
DateTime.ParseExact(monthName, "MMMM", CultureInfo.CurrentCulture ).Month
Although, for your purposes, you'll probably be better off just creating a Dictionary<string, int> mapping the month's name to its value.
Solution 2 - C#
You could do something like this:
Convert.ToDate(month + " 01, 1900").Month
Solution 3 - C#
If you use the DateTime.ParseExact()-method that several people have suggested, you should carefully consider what you want to happen when the application runs in a non-English environment!
In Denmark, which of ParseExact("Januar", ...) and ParseExact("January", ...) should work and which should fail?
That will be the difference between CultureInfo.CurrentCulture and CultureInfo.InvariantCulture.
Solution 4 - C#
One simply solution would be create a Dictionary with names and values. Then using Contains() you can find the right value.
Dictionary<string, string> months = new Dictionary<string, string>()
{
{ "january", "01"},
{ "february", "02"},
{ "march", "03"},
{ "april", "04"},
{ "may", "05"},
{ "june", "06"},
{ "july", "07"},
{ "august", "08"},
{ "september", "09"},
{ "october", "10"},
{ "november", "11"},
{ "december", "12"},
};
foreach (var month in months)
{
if (StringThatContainsMonth.ToLower().Contains(month.Key))
{
string thisMonth = month.Value;
}
}
Solution 5 - C#
You can use the DateTime.Parse method to get a DateTime object and then check its Month property. Do something like this:
int month = DateTime.Parse("1." + monthName + " 2008").Month;
The trick is to build a valid date to create a DateTime object.
Solution 6 - C#
You can use an enum of months:
public enum Month
{
January,
February,
// (...)
December,
}
public Month ToInt(Month Input)
{
return (int)Enum.Parse(typeof(Month), Input, true));
}
I am not 100% certain on the syntax for enum.Parse(), though.
Solution 7 - C#
You don't have to create a DateTime instance to do this. It's as simple as this:
public static class Month
{
public static int ToInt(this string month)
{
return Array.IndexOf(
CultureInfo.CurrentCulture.DateTimeFormat.MonthNames,
month.ToLower(CultureInfo.CurrentCulture))
+ 1;
}
}
I'm running on the da-DK culture, so this unit test passes:
[Theory]
[InlineData("Januar", 1)]
[InlineData("Februar", 2)]
[InlineData("Marts", 3)]
[InlineData("April", 4)]
[InlineData("Maj", 5)]
[InlineData("Juni", 6)]
[InlineData("Juli", 7)]
[InlineData("August", 8)]
[InlineData("September", 9)]
[InlineData("Oktober", 10)]
[InlineData("November", 11)]
[InlineData("December", 12)]
public void Test(string monthName, int expected)
{
var actual = monthName.ToInt();
Assert.Equal(expected, actual);
}
I'll leave it as an exercise to the reader to create an overload where you can pass in an explicit CultureInfo.
Solution 8 - C#
And answering this seven years after the question was asked, it is possible to do this comparison using built-in methods:
Month.toInt("January") > Month.toInt("May")
becomes
Array.FindIndex( CultureInfo.CurrentCulture.DateTimeFormat.MonthNames,
t => t.Equals("January", StringComparison.CurrentCultureIgnoreCase)) >
Array.FindIndex( CultureInfo.CurrentCulture.DateTimeFormat.MonthNames,
t => t.Equals("May", StringComparison.CurrentCultureIgnoreCase))
Which can be refactored into an extension method for simplicity. The following is a LINQPad example (hence the Dump() method calls):
void Main()
{
("January".GetMonthIndex() > "May".GetMonthIndex()).Dump();
("January".GetMonthIndex() == "january".GetMonthIndex()).Dump();
("January".GetMonthIndex() < "May".GetMonthIndex()).Dump();
}
public static class Extension {
public static int GetMonthIndex(this string month) {
return Array.FindIndex( CultureInfo.CurrentCulture.DateTimeFormat.MonthNames,
t => t.Equals(month, StringComparison.CurrentCultureIgnoreCase));
}
}
With output:
False
True
True
Solution 9 - C#
If you are using c# 3.0 (or above) you can use extenders
Solution 10 - C#
Public Function returnMonthNumber(ByVal monthName As String) As Integer
Select Case monthName.ToLower
Case Is = "january"
Return 1
Case Is = "february"
Return 2
Case Is = "march"
Return 3
Case Is = "april"
Return 4
Case Is = "may"
Return 5
Case Is = "june"
Return 6
Case Is = "july"
Return 7
Case Is = "august"
Return 8
Case Is = "september"
Return 9
Case Is = "october"
Return 10
Case Is = "november"
Return 11
Case Is = "december"
Return 12
Case Else
Return 0
End Select
End Function
caution code is in Beta version.
Solution 11 - C#
I translate it into C# code in Spanish version, regards:
public string ObtenerNumeroMes(string NombreMes){
string NumeroMes;
switch(NombreMes) {
case ("ENERO") :
NumeroMes = "01";
return NumeroMes;
case ("FEBRERO") :
NumeroMes = "02";
return NumeroMes;
case ("MARZO") :
NumeroMes = "03";
return NumeroMes;
case ("ABRIL") :
NumeroMes = "04";
return NumeroMes;
case ("MAYO") :
NumeroMes = "05";
return NumeroMes;
case ("JUNIO") :
NumeroMes = "06";
return NumeroMes;
case ("JULIO") :
NumeroMes = "07";
return NumeroMes;
case ("AGOSTO") :
NumeroMes = "08";
return NumeroMes;
case ("SEPTIEMBRE") :
NumeroMes = "09";
return NumeroMes;
case ("OCTUBRE") :
NumeroMes = "10";
return NumeroMes;
case ("NOVIEMBRE") :
NumeroMes = "11";
return NumeroMes;
case ("DICIEMBRE") :
NumeroMes = "12";
return NumeroMes;
default:
Console.WriteLine("Error");
return "ERROR";
}
}
Solution 12 - C#
What I did was to use SimpleDateFormat to create a format string, and parse the text to a date, and then retrieve the month from that. The code is below:
int year = 2012 \\or any other year
String monthName = "January" \\or any other month
SimpleDateFormat format = new SimpleDateFormat("dd-MMM-yyyy");
int monthNumber = format.parse("01-" + monthName + "-" + year).getMonth();
Solution 13 - C#
This code helps you...
using System.Globalization;
....
string FullMonthName = CultureInfo.CurrentCulture.DateTimeFormat.GetMonthName(DateTime.UtcNow.Month);
GetMonthName Method - it returns string...
If you want to get a month as an integer, then simply use -
DateTime dt= DateTime.UtcNow;
int month= dt.Month;
I hope, it helps you!!!
Thanks!!!
Solution 14 - C#
int selectedValue = 0;
switch (curentMonth)
{
case "January":
selectedValue = 1;
break;
case "February":
selectedValue = 2;
break;
}
if (selectedValue != 0)
{
/* var list= db.model_name.Where(x => x.column== selectedValue);
return list; */
}
return Ok(selectedValue);