.NET: Are there any differences between InvariantCulture and en-US?

Given the following two cultures:

CultureInfo c1 = InvariantCulture;
CultureInfo c2 = new CultureInfo("en-US");

and i were to examine every piece of information specific to both cultures, e.g.:

c1.DateTimeInfo.ShortDatePattern;
c2.DateTimeInfo.ShortDatePattern;

c1.DateTimeInfo.LongDatePattern;
c2.DateTimeInfo.LongDatePattern;

c1.NumberFormat.CurrencyDecimalDigits;
c2.NumberFormat.CurrencyDecimalDigits;

c1.TextInfo.IsRightToLeft;
c2.TextInfo.IsRightToLeft;

Would i find any differences?

In other words, is the InvariantCulture, for all purposes, identical to the "en-US" culture?

Solution 1:

Yes.

For example: InvariantCulture uses the international symbol for currency: "¤" versus the dollar sign: "$" when formatting currency.

For the most part, however, they're very similar.

Solution 2:

There are some actual differences (check both values in a Watch window), but the most relevant difference is the intent. InvariantCulture shows your intent of parsing some data in a culture independent, if english related, manner, whereas en-US declares your actual intent to parse data in a US specific manner.

Solution 3:

Well, if you look at what your snippet of code might produce:

CultureInfo c1 = CultureInfo.InvariantCulture;
CultureInfo c2 = new CultureInfo("en-US");

Console.WriteLine( c1.DateTimeFormat.ShortDatePattern.ToString());
Console.WriteLine( c2.DateTimeFormat.ShortDatePattern.ToString());

Console.WriteLine( c1.DateTimeFormat.LongDatePattern.ToString());
Console.WriteLine( c2.DateTimeFormat.LongDatePattern.ToString());

Console.WriteLine( c1.NumberFormat.CurrencyDecimalDigits.ToString());
Console.WriteLine( c2.NumberFormat.CurrencyDecimalDigits.ToString());

Console.WriteLine( c1.TextInfo.IsRightToLeft.ToString());
Console.WriteLine( c2.TextInfo.IsRightToLeft.ToString());

You'll see some differences:

MM/dd/yyyy
M/d/yyyy
dddd, dd MMMM yyyy
dddd, MMMM dd, yyyy
2
2
False
False

And just think, when the US loses it's backbone and decides to start using European style dates or moves to the metric system (the metric system is the tool of the devil! My car gets forty rods to the hogshead and that's the way I likes it!), the InvariantCulture can just coolly and smoothly stay the way it is. So all those dates you've stashed away in a database in text form using the InvariantCulture will continue to just work...

Solution 4:

It is very important to consider the intent of the data. If you are serializing make sure to use InvariantCulture.

See: http://msdn.microsoft.com/en-us/library/system.globalization.cultureinfo.aspx

From the microsoft documentation:

Dynamic Culture Data

Except for the invariant culture, culture data is dynamic. This is true even for the predefined cultures. ...

Caution

When saving data, your application should use the invariant culture, use a binary format, or use a specific culture-independent format. Data saved according to the current values associated with a particular culture, other than the invariant culture, might become unreadable or might change in meaning if that culture changes.

I just encountered this recently where the user had his Region and Language settings set to English (United States), but had chosen his personal date format to dd-MMM-yy. He received a project from a client with a date in the default en-US format "4/29/2010 1:45:30 PM" and the code:

customValue = DateTime.Parse(customValue.ToString(), CultureInfo.CreateSpecificCulture("en-US"));

threw an exception because his local preferences override what the typical en-US format.

Solution 5:

Short answer yes. InvariantCulture is what it says, not a specific culture. It is english, but not a specific region

you can read more about it here : MSDN