Returns a string representation of this Locale
object, consisting of language, country, variant, script,
and extensions as below:
language + "_" + country + "_" + (variant + "_#" | "#") + script + "-" + extensionsLanguage is always lower case, country is always upper case, script is always title case, and extensions are always lower case. Extensions and private use subtags will be in canonical order as explained in
toLanguageTag.
When the locale has neither script nor extensions, the result is the same as in Java 6 and prior.
If both the language and country fields are missing, this function will return the empty string, even if the variant, script, or extensions field is present (you can't have a locale with just a variant, the variant must accompany a well-formed language or country code).
If script or extensions are present and variant is missing, no underscore is added before the "#".
This behavior is designed to support debugging and to be compatible with
previous uses of toString that expected language, country, and variant
fields only. To represent a Locale as a String for interchange purposes, use
toLanguageTag.
Examples:
getDisplayName, toLanguageTag
Diagram: Locale