Number.prototype.toLocaleString()
The toLocaleString()
method returns a string with a
language-sensitive representation of this number.
Syntax
toLocaleString()
toLocaleString(locales)
toLocaleString(locales, options)
Parameters
The locales
and options
arguments customize the behavior of
the function and let applications specify the language whose formatting conventions
should be used. In implementations, which ignore the locales
and
options
arguments, the locale used and the form of the string returned are
entirely implementation dependent.
See the Intl.NumberFormat()
constructor
for details on these parameters and how to use them.
Return value
A string with a language-sensitive representation of the given number.
Performance
When formatting large numbers of numbers, it is better to create a
Intl.NumberFormat
object and use the function provided by its
format
property.
Examples
Using toLocaleString
In basic use without specifying a locale, a formatted string in the default locale and with default options is returned.
var number = 3500;
console.log(number.toLocaleString()); // Displays "3,500" if in U.S. English locale
Checking for support for locales
and options
arguments
The locales
and options
arguments are not supported in all
browsers yet. To check for support in ES5.1 and later implementations, the requirement
that illegal language tags are rejected with a RangeError
exception can be used:
function toLocaleStringSupportsLocales() {
var number = 0;
try {
number.toLocaleString('i');
} catch (e) {
return e.name === 'RangeError';
}
return false;
}
Prior to ES5.1, implementations were not required to throw a range error exception if
toLocaleString
is called with arguments.
A check that works in all hosts, including those supporting ECMA-262 prior to ed 5.1,
is to test for the features specified in ECMA-402 that are required to support regional
options for Number.prototype.toLocaleString
directly:
function toLocaleStringSupportsOptions() {
return !!(typeof Intl == 'object' && Intl && typeof Intl.NumberFormat == 'function');
}
This tests for a global Intl
object, checks that it's not
null
and that it has a NumberFormat
property that is a
function.
Using locales
This example shows some of the variations in localized number formats. In order to get
the format of the language used in the user interface of your application, make sure to
specify that language (and possibly some fallback languages) using the
locales
argument:
var number = 123456.789;
// German uses comma as decimal separator and period for thousands
console.log(number.toLocaleString('de-DE'));
// → 123.456,789
// Arabic in most Arabic speaking countries uses Eastern Arabic digits
console.log(number.toLocaleString('ar-EG'));
// → ١٢٣٤٥٦٫٧٨٩
// India uses thousands/lakh/crore separators
console.log(number.toLocaleString('en-IN'));
// → 1,23,456.789
// the nu extension key requests a numbering system, e.g. Chinese decimal
console.log(number.toLocaleString('zh-Hans-CN-u-nu-hanidec'));
// → 一二三,四五六.七八九
// when requesting a language that may not be supported, such as
// Balinese, include a fallback language, in this case Indonesian
console.log(number.toLocaleString(['ban', 'id']));
// → 123.456,789
Using options
The results provided by toLocaleString
can be customized using the
options
argument:
var number = 123456.789;
// request a currency format
console.log(number.toLocaleString('de-DE', { style: 'currency', currency: 'EUR' }));
// → 123.456,79 €
// the Japanese yen doesn't use a minor unit
console.log(number.toLocaleString('ja-JP', { style: 'currency', currency: 'JPY' }))
// → ¥123,457
// limit to three significant digits
console.log(number.toLocaleString('en-IN', { maximumSignificantDigits: 3 }));
// → 1,23,000
// Use the host default language with options for number formatting
var num = 30000.65;
console.log(num.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2}));
// → "30,000.65" where English is the default language, or
// → "30.000,65" where German is the default language, or
// → "30 000,65" where French is the default language
Specifications
Specification |
---|
ECMAScript Language Specification # sec-number.prototype.tolocalestring |
ECMAScript Internationalization API Specification # sup-number.prototype.tolocalestring |
Browser compatibility
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