Intl.NumberFormat.prototype.resolvedOptions()

The Intl.NumberFormat.prototype.resolvedOptions() method returns a new object with properties reflecting the locale and number formatting options computed during initialization of this NumberFormat object.

numberFormat.resolvedOptions()

A new object with properties reflecting the locale and number formatting options computed during the initialization of the given NumberFormat object.

The resulting object has the following properties:

locale

The BCP 47 language tag for the locale actually used. If any Unicode extension values were requested in the input BCP 47 language tag that led to this locale, the key-value pairs that were requested and are supported for this locale are included in locale.

numberingSystem

The value provided for this properties in the options argument, if present, or the value requested using the Unicode extension key "nu" or filled in as a default.

notation

The value provided for this property in the options argument, if present, or "standard" filled in as a default.

compactDisplay

The value provided for this property in the options argument, or "short" filled in as a default. 
This property is only present if the notation is set to "compact". 

signDisplay

The value provided for this property in the options argument, or "auto" filled in as a default. 

useGrouping

The values provided for these properties in the options argument or filled in as defaults.

currency

currencyDisplay

The values provided for these properties in the options argument or filled in as defaults. These properties are only present if style is "currency".

Only one of the following two groups of properties is included:

minimumIntegerDigits

minimumFractionDigits

maximumFractionDigits

The values provided for these properties in the options argument or filled in as defaults. These properties are present only if neither minimumSignificantDigits nor maximumSignificantDigits was provided in the options argument.

minimumSignificantDigits

maximumSignificantDigits

The values provided for these properties in the options argument or filled in as defaults. These properties are present only if at least one of them was provided in the options argument.

var de = new Intl.NumberFormat('de-DE');
var usedOptions = de.resolvedOptions();

usedOptions.locale;                // "de-DE"
usedOptions.numberingSystem;       // "latn"
usedOptions.notation;              // "standard"
usedOptions.signDisplay;           // "auto"
usedOption.style;                  // "decimal"
usedOptions.minimumIntegerDigits;  // 1
usedOptions.minimumFractionDigits; // 0
usedOptions.maximumFractionDigits; // 3
usedOptions.useGrouping;           // true

• Intl.NumberFormat