See class description. Generally set once when your applet or application is initialized, then never reset. More advanced programs will allow users to use different locales for different fields, e.g. in a spreadsheet. Note that the initial setting will match the host system. Normally set once at the beginning of applet or application, then never reset.
Language is always lower case, and country is always uppcer case.
If a field is missing, at most one underbar will occur. Returns the empty string if the locale doesn't specify a language. Returns the empty string if the locale doesn't specify a country. This will be the name the locale's language localized for the default locale, if that data is available. If the locale doesn't specify a language, this function returns the empty string.