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概述
toLocaleString()
方法返回这个数字在特定语言环境下的表示字符串。
The new locales
and options
arguments let applications specify the language whose formatting conventions should be used and customize the behavior of the function. In older implementations, which ignore the locales
and options
arguments, the locale used and the form of the string returned are entirely implementation dependent.
语法
numObj.toLocaleString(
[locales [, options]])
参数
Check the Browser compatibility section to see which browsers support the locales
and options
arguments, and the Example: Checking for support for locales
and options
arguments for feature detection.
ECMAScript Internationalization API, implemented with Firefox 29, added the locales
argument to the Number.toLocaleString
method. If the argument is undefined
, this method returns localized digits specified by the OS, while the previous versions of Firefox returned English digits. This change has been reported as a regression affecting backward compatibility which might be fixed soon. (bug 999003)
locales
-
Optional. A string with a BCP 47 language tag, or an array of such strings. For the general form and interpretation of the
locales
argument, see the Intl page. The following Unicode extension key is allowed:nu
- The numbering system to be used. Possible values include:
"arab"
,"arabext"
,"bali"
,"beng"
,"deva"
,"fullwide"
,"gujr"
,"guru"
,"hanidec"
,"khmr"
,"knda"
,"laoo"
,"latn"
,"limb"
,"mlym"
,"mong"
,"mymr"
,"orya"
,"tamldec"
,"telu"
,"thai"
,"tibt"
.
options
-
Optional. An object with some or all of the following properties:
localeMatcher
- The locale matching algorithm to use. Possible values are
"lookup"
and"best fit"
; the default is"best fit"
. For information about this option, see the Intl page. style
- The formatting style to use. Possible values are
"decimal"
for plain number formatting,"currency"
for currency formatting, and"percent"
for percent formatting; the default is"decimal"
. currency
- The currency to use in currency formatting. Possible values are the ISO 4217 currency codes, such as
"USD"
for the US dollar,"EUR"
for the euro, or"CNY"
for the Chinese RMB — see the Current currency & funds code list. There is no default value; if thestyle
is"currency"
, thecurrency
property must be provided. currencyDisplay
- How to display the currency in currency formatting. Possible values are
"symbol"
to use a localized currency symbol such as €,"code"
to use the ISO currency code,"name"
to use a localized currency name such as"dollar"
; the default is"symbol"
. useGrouping
- Whether to use grouping separators, such as thousands separators or thousand/lakh/crore separators. Possible values are
true
andfalse
; the default istrue
.
The following properties fall into two groups:
minimumIntegerDigits
,minimumFractionDigits
, andmaximumFractionDigits
in one group,minimumSignificantDigits
andmaximumSignificantDigits
in the other. If at least one property from the second group is defined, then the first group is ignored.minimumIntegerDigits
- The minimum number of integer digits to use. Possible values are from 1 to 21; the default is 1.
minimumFractionDigits
- The minimum number of fraction digits to use. Possible values are from 0 to 20; the default for plain number and percent formatting is 0; the default for currency formatting is the number of minor unit digits provided by the ISO 4217 currency code list (2 if the list doesn't provide that information).
maximumFractionDigits
- The maximum number of fraction digits to use. Possible values are from 0 to 20; the default for plain number formatting is the larger of
minimumFractionDigits
and 3; the default for currency formatting is the larger ofminimumFractionDigits
and the number of minor unit digits provided by the ISO 4217 currency code list (2 if the list doesn't provide that information); the default for percent formatting is the larger ofminimumFractionDigits
and 0. minimumSignificantDigits
- The minimum number of significant digits to use. Possible values are from 1 to 21; the default is 1.
maximumSignificantDigits
- The maximum number of significant digits to use. Possible values are from 1 to 21; the default is
minimumSignificantDigits
.
示例
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
Example: Checking for support for locales
and options
arguments
The locales
and options
arguments are not supported in all browsers yet. To check whether an implementation supports them already, you can use the requirement that illegal language tags are rejected with a RangeError
exception:
function toLocaleStringSupportsLocales() { var number = 0; try { number.toLocaleString("i"); } catch (e) { return e.name === "RangeError"; } return false; }
Example: 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 alert(number.toLocaleString("de-DE")); // → 123.456,789 // Arabic in most Arabic speaking countries uses real Arabic digits alert(number.toLocaleString("ar-EG")); // → ١٢٣٤٥٦٫٧٨٩ // India uses thousands/lakh/crore separators alert(number.toLocaleString("en-IN")); // → 1,23,456.789 // the nu extension key requests a numbering system, e.g. Chinese decimal alert(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 alert(number.toLocaleString(["ban", "id"])); // → 123.456,789
Example: Using options
The results provided by toLocaleString
can be customized using the options
argument:
var number = 123456.789; // request a currency format alert(number.toLocaleString("de-DE", {style: "currency", currency: "EUR"})); // → 123.456,79 € // the Japanese yen doesn't use a minor unit alert(number.toLocaleString("ja-JP", {style: "currency", currency: "JPY"})) // → ¥123,457 // limit to three significant digits alert(number.toLocaleString("en-IN", {maximumSignificantDigits: 3})); // → 1,23,000
性能
When formatting large numbers of numbers, it is better to create a NumberFormat
object and use the function provided by its NumberFormat.format
property.
规范
规范版本 | 规范状态 | 注解 |
---|---|---|
ECMAScript 3rd Edition. Implemented in JavaScript 1.5 | Standard | Initial definition. |
ECMAScript 5.1 (ECMA-262) Number.prototype.toLocaleString |
Standard | |
ECMAScript 2015 (6th Edition, ECMA-262) Number.prototype.toLocaleString |
Standard | |
ECMAScript Internationalization API Specification, 1st Edition (ECMA-402) | Standard |
浏览器兼容性
Feature | Chrome | Firefox (Gecko) | Internet Explorer | Opera | Safari (WebKit) |
---|---|---|---|---|---|
Basic support | (Yes) | (Yes) | (Yes) | (Yes) | (Yes) |
locales and options arguments |
24 |
29 (29) |
11 | 15 | 10 |
Feature | Android | Chrome for Android | Firefox Mobile (Gecko) | IE Mobile | Opera Mobile | Safari Mobile |
---|---|---|---|---|---|---|
Basic support | (Yes) | (Yes) | (Yes) | (Yes) | (Yes) | (Yes) |
locales and options arguments |
未实现 | 26 |
未实现 |
未实现 | 未实现 | 未实现 |