Return the locale that was used to construct this number formatter object.
If the locale was not given as parameter to the constructor, this method returns the default
locale of the system.
Returns the rounding mode set up in the constructor.
The rounding mode controls how numbers are rounded when the integral or fraction digits
of a number are limited.
Return the style that was used to construct this number formatter object.
Valid values are for "currency": "common" (symbol) or "iso" (ISO code).
for "number": "standard", "scientific", "native", or "nogrouping".