Intl.ListFormat.prototype.formatToParts()

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since April 2021.

The formatToParts() method of Intl.ListFormat 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.

Try it

const vehicles = ["Motorcycle", "Bus", "Car"];

const formatterEn = new Intl.ListFormat("en", {
  style: "long",
  type: "conjunction",
});

const formatterFr = new Intl.ListFormat("fr", {
  style: "long",
  type: "conjunction",
});

const partValuesEn = formatterEn.formatToParts(vehicles).map((p) => p.value);
const partValuesFr = formatterFr.formatToParts(vehicles).map((p) => p.value);

console.log(partValuesEn);
// Expected output: "["Motorcycle", ", ", "Bus", ", and ", "Car"]"
console.log(partValuesFr);
// Expected output: "["Motorcycle", ", ", "Bus", " et ", "Car"]"

Syntax

js
formatToParts(list)

Parameters

list

An iterable object, such as an Array, containing strings. Omitting it results in formatting the empty array, which could be slightly confusing, so it is advisable to always explicitly pass a list.

Return value

An Array of objects containing the formatted list in parts. Each object has two properties, type and value, each containing a string. The string concatenation of value, in the order provided, will result in the same string as format(). The type may be one of the following:

literal

Any string that's a part of the format pattern; for example ", ", ", and", etc.

element

An element of the list, exactly as provided.

Examples

Using formatToParts()

js
const fruits = ["Apple", "Orange", "Pineapple"];
const myListFormat = new Intl.ListFormat("en-GB", {
  style: "long",
  type: "conjunction",
});

console.table(myListFormat.formatToParts(fruits));
// [
//  { "type": "element", "value": "Apple" },
//  { "type": "literal", "value": ", " },
//  { "type": "element", "value": "Orange" },
//  { "type": "literal", "value": " and " },
//  { "type": "element", "value": "Pineapple" }
// ]

Specifications

Specification
ECMAScript® 2025 Internationalization API Specification
# sec-Intl.ListFormat.prototype.formatToParts

Browser compatibility

BCD tables only load in the browser

See also