Intl.DurationFormat.prototype.formatToParts()

The formatToParts() method of Intl.DurationFormat instances returns an array of objects representing each part of the formatted string that would be returned by format(). It is useful for building custom strings from the locale-specific tokens.

Syntax

formatToParts(duration)

Parameters

duration Optional

The duration object to be formatted. It should include some or all of the following properties: years, months, weeks, days, hours, minutes, seconds, milliseconds, microseconds, nanoseconds. Each property's value should be an integer, and their signs should be consistent. This can be a Temporal.Duration object; see the Temporal.Duration documentation for more information about these properties.

Return value

An Array of objects containing the formatted duration in parts. Each object has two or three properties, type, value, and optionally unit, each containing a string. The string concatenation of value, in the order provided, will result in the same string as format(). The parts can be thought of as directly obtained from calling Intl.NumberFormat.prototype.formatToParts() with the numeric value and their respective units. All tokens that are produced by the NumberFormat have an additional unit property, which is the singular form of the input unit; this is for programmatic usage and is not localized. The localized unit is output as a separate unit token as part of the NumberFormat result. The parts from each duration unit are concatenated together in the same fashion as calling Intl.ListFormat.prototype.formatToParts() with { type: "unit" }, so additional literal tokens are inserted.

Examples

The formatToParts method enables locale-aware formatting of strings produced by DurationFormat formatters by providing you the string in parts:

const duration = {
  hours: 7,
  minutes: 8,
  seconds: 9,
  milliseconds: 123,
  microseconds: 456,
  nanoseconds: 789,
};

new Intl.DurationFormat("en", { style: "long" }).formatToParts(duration);

// Returned value:
[
  { type: "integer", value: "7", unit: "hour" },
  { type: "literal", value: " ", unit: "hour" },
  { type: "unit", value: "hours", unit: "hour" },
  { type: "literal", value: ", " },
  { type: "integer", value: "8", unit: "minute" },
  { type: "literal", value: " ", unit: "minute" },
  { type: "unit", value: "minutes", unit: "minute" },
  { type: "literal", value: ", " },
  { type: "integer", value: "9", unit: "second" },
  { type: "literal", value: " ", unit: "second" },
  { type: "unit", value: "seconds", unit: "second" },
  { type: "literal", value: ", " },
  { type: "integer", value: "123", unit: "millisecond" },
  { type: "literal", value: " ", unit: "millisecond" },
  { type: "unit", value: "milliseconds", unit: "millisecond" },
  { type: "literal", value: ", " },
  { type: "integer", value: "456", unit: "microsecond" },
  { type: "literal", value: " ", unit: "microsecond" },
  { type: "unit", value: "microseconds", unit: "microsecond" },
  { type: "literal", value: ", " },
  { type: "integer", value: "789", unit: "nanosecond" },
  { type: "literal", value: " ", unit: "nanosecond" },
  { type: "unit", value: "nanoseconds", unit: "nanosecond" },
];

Specifications

Browser compatibility

See also

• Intl.DurationFormat
• Intl.DurationFormat.prototype.format()
• Temporal.Duration