CODEWITHSUNDEEP
c#parsingintegercompare
spilliton
spilliton

Reputation: 3921

How to parse a month name (string) to an integer for comparison in C#?

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?

Upvotes: 109

Views: 166401

Answers (16)

Gucu112
Gucu112

Reputation: 957

I did something like this:

var culture = System.Globalization.CultureInfo.CreateSpecificCulture("pl");
DateTime.ParseExact("Luty", "MMMM", culture).Month

You can specify any other culture to match your preferences :)

Upvotes: 0

RARE Kpop Manifesto
RARE Kpop Manifesto

Reputation: 2865

This code is for awk, but easily adaptable to C/C++/C#

— in awk, all indices are "1-based" instead of "0-based" - the leading edge "=" of the reference string is simply pre-shifting the positions. remove that "=" for any 0-based languages`

function __(_) {  #  input - Eng. month names, any casing, min. 3 letters
                  # output - MM : [01-12], zero-padded
    return \
    ((_=toupper(_)) ~ "^[OND]" ? "" : _<_) \
    (index("=ANEBARPRAYUNULUGEPCTOVEC", substr(_ "",_+=_^=_<_,_))/_)
}

The reference string might look odd at first -

the 2nd + 3rd letters of month names constitute a unique set

So OP can input the english name of the months, full or abbreviated, and it'll return a zero-padded 2-digit month number. If you need it to be in integer form, then just scrub out the middle line that performs the padding.

You'll notice only 1 input variable declared and no other temp variables whatsoever - one of awk's major strengths is its extreme agility when it comes to dynamic typing of variables, even for truly illogical operations like taking the "0th-power" of a string variable like

"Boston" ^ 0

This would seamlessly coerce that variable to a numeric data type, with a new value of 1.

This flexibility enables the recycling and re-using of the input temp variable(s) for any other purpose the moment the original input value(s) is/are no longer needed.

Upvotes: 0

user15276771
user15276771

Reputation: 11

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);

Upvotes: 0

Nitika Chopra
Nitika Chopra

Reputation: 1405

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!!!

Upvotes: -1

Carlos A. Ortiz
Carlos A. Ortiz

Reputation: 169

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;
    }
}

Upvotes: 10

David Clarke
David Clarke

Reputation: 13266

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

Upvotes: 2

Maria Carolina Araujo
Maria Carolina Araujo

Reputation: 11

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";

        }

   }

Upvotes: 1

Rasmus Faber
Rasmus Faber

Reputation: 49677

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.

Upvotes: 20

Mark Seemann
Mark Seemann

Reputation: 233277

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.

Upvotes: 9

Ebenezer Ampiah
Ebenezer Ampiah

Reputation: 17

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();

Upvotes: 0

Treb
Treb

Reputation: 20289

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.

Upvotes: 9

Thabiso
Thabiso

Reputation: 51

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.

Upvotes: 3

James Curran
James Curran

Reputation: 103535

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.

Upvotes: 203

Rune Grimstad
Rune Grimstad

Reputation: 36330

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.

Upvotes: 9

Aaron Palmer
Aaron Palmer

Reputation: 9002

You could do something like this:

Convert.ToDate(month + " 01, 1900").Month

Upvotes: 25

Adam Naylor
Adam Naylor

Reputation: 6340

If you are using c# 3.0 (or above) you can use extenders

Upvotes: 1

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