Note: This is not a real constructor, but just a description of the type of object that should be passed as
a parameter to some method(s), and/or the return value from some method(s).
In other words, the type exists only for documentation purposes, and you cannot call new number.__FormatOptions()
If false, show no decimal places, overriding places and pattern settings.
override formatting pattern with this string. Default value is based on locale. Overriding this property will defeat localization. Literal characters in patterns are not supported.
fixed number of decimal places to show. This overrides any information in the provided pattern.
5 rounds to nearest .5; 0 rounds to nearest whole (default). -1 means do not round.
choose a format type based on the locale from the following: decimal, scientific (not yet supported), percent, currency. decimal by default.