MICROSOFT_PRESS_EBOOK_PROGRAMMING_WINDOWS_8_APPS_WITH_HTML_CSS_AND_JAVASCRIPT_PDF

Group integers
var currencyFormatUSD2 =
new Windows.Globalization.NumberFormatting.CurrencyFormatter("USD");
currencyFormatUSD2.isGrouped = 1;
var currencyUSD2 = currencyFormatUSD2.format(fractionalNumber);
The output of this code is as follows:
The other number formatters all work like this, so I’ll leave it to you to check out the details in the
documentation and the sample.
To format dates and time, we can turn to the Windows.Globalization.DateTimeFormatting
namespace where we find the DateTimeFormatter class along with many enumerations for the different
ways to formats seconds, minutes, hours, days, months, and years. To use the API, you instantiate a
formatter object specifying the desired formats and applicable languages. (There are no less than eight
separate constructors here!) You then set options like the clock, geographicRegion, and so forth and call
its format method with the Date value you need to format. You can even apply custom formats if
desired. Many such variations are demonstrated in the Date and time formatting sample; I trust a simple
snippet of its code will suffice here (from Scenario 2, js/stringtemplate.js);
var mydatefmt1 = new Windows.Globalization.DateTimeFormatting.DateTimeFormatter(
"month day");
var mytimefmt1 = new Windows.Globalization.DateTimeFormatting.DateTimeFormatter(
"hour minute ");
var dateToFormat = new Date();
var mydate1 = mydatefmt1.format(dateToFormat);
var mytime1 = mytimefmt1.format(dateToFormat);
The other bit of code from the SDK that’s relevant here is the Calendar details and math sample. As
mentioned earlier in this chapter when I described expiration times for app trials and in-app purchases,
a world-ready app must not make assumptions about how time periods are computed or compared
because this can vary depending on regional calendars. This is why the extensive
Windows.-Globalization.Calendar class contains ten distinct add* methods that range from
addNanoseconds to addEras, along with its compare and compareDateTime methods (and a bunch to get
all the little bits of calendar-related text). In other words, drill it into your mind now to never, ever use
arithmetic operators on date and time values because they won’t work properly in every locale. Even in
the United States you’ll end up getting wrong answers at times because you won’t be taking things like
daylight savings time into account, where the number of hours in two days of every year will not
actually be 24!
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