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概述
The toLocaleTimeString()
方法返回该日期对象时间部分的字符串,该字符串格式因不同语言而不同。新增的参数 locales
和 options
使程序能够指定使用哪种语言格式化规则,允许定制该方法的表现(behavior)。在旧版本浏览器中, locales
和 options
参数被忽略,使用的语言环境和返回的字符串格式是各自独立实现的。
语法
dateObj.toLocaleTimeString([locales [, options]])
参数
查看浏览器兼容性小节,看下哪些浏览器支持 locales
和 options
参数,还可以参看例子:检测 locales
和 options
参数支持情况。
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 keys are allowed:nu
- Numbering system. 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"
. ca
- Calendar. Possible values include:
"buddhist"
,"chinese"
,"coptic"
,"ethioaa"
,"ethiopic"
,"gregory"
,"hebrew"
,"indian"
,"islamic"
,"islamicc"
,"iso8601"
,"japanese"
,"persian"
,"roc"
.
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. timeZone
- The time zone to use. The only value implementations must recognize is
"UTC"
; the default is the runtime's default time zone. Implementations may also recognize the time zone names of the IANA time zone database, such as"Asia/Shanghai"
,"Asia/Kolkata"
,"America/New_York"
. hour12
- Whether to use 12-hour time (as opposed to 24-hour time). Possible values are
true
andfalse
; the default is locale dependent. formatMatcher
- The format matching algorithm to use. Possible values are
"basic"
and"best fit"
; the default is"best fit"
. See the following paragraphs for information about the use of this property.
The following properties describe the date-time components to use in formatted output, and their desired representations. Implementations are required to support at least the following subsets:
weekday
,year
,month
,day
,hour
,minute
,second
weekday
,year
,month
,day
year
,month
,day
year
,month
month
,day
hour
,minute
,second
hour
,minute
Implementations may support other subsets, and requests will be negotiated against all available subset-representation combinations to find the best match. Two algorithms are available for this negotiation and selected by the
formatMatcher
property: A fully specified"basic"
algorithm and an implementation dependent"best fit"
algorithm.weekday
- The representation of the weekday. Possible values are
"narrow"
,"short"
,"long"
. era
- The representation of the era. Possible values are
"narrow"
,"short"
,"long"
. year
- The representation of the year. Possible values are
"numeric"
,"2-digit"
. month
- The representation of the month. Possible values are
"numeric"
,"2-digit"
,"narrow"
,"short"
,"long"
. day
- The representation of the day. Possible values are
"numeric"
,"2-digit"
. hour
- The representation of the hour. Possible values are
"numeric"
,"2-digit"
. minute
- The representation of the minute. Possible values are
"numeric"
,"2-digit"
. second
- The representation of the second. Possible values are
"numeric"
,"2-digit"
. timeZoneName
- The representation of the time zone name. Possible values are
"short"
,"long"
.
The default value for each date-time component property is undefined
, but if the hour
, minute
, second
properties are all undefined
, then hour
, minute
, and second
are assumed to be "numeric".
例子
例子:使用 toLocaleTimeString
没有指定语言环境(locale)时,返回一个使用默认语言环境和格式设置(options)的格式化字符串。
var date = new Date(Date.UTC(2012, 11, 12, 3, 0, 0)); // toLocaleTimeString without arguments depends on the implementation, // the default locale, and the default time zone alert(date.toLocaleTimeString()); // → "7:00:00 PM" if run in en-US locale with time zone America/Los_Angeles
例子:检测 locales
和 options
支持情况
locales
和 options
参数不是所有的浏览器都支持。为了检测一种实现环境(implementation)是否支持它们,可以使用不合法的语言标签,如果实现环境支持该参数,则会抛出一个 RangeError
异常,反之会忽略参数。
function toLocaleTimeStringSupportsLocales() { try { new Date().toLocaleTimeString("i"); } catch (e) { return e.name === "RangeError"; } return false; }
例子:使用 locales
参数
下例展示了本地化时间格式的一些变化。为了在应用的用户界面得到某种语言的时间格式,必须确保使用 locales
参数指定了该语言(可能还需要设置某些回退语言)。
var date = new Date(Date.UTC(2012, 11, 20, 3, 0, 0));
// formats below assume the local time zone of the locale;
// America/Los_Angeles for the US
// US English uses 12-hour time with AM/PM
alert(date.toLocaleTimeString("en-US"));
// → "7:00:00 PM"
// British English uses 24-hour time without AM/PM
alert(date.toLocaleTimeString("en-GB"));
// → "03:00:00"
// Korean uses 12-hour time with AM/PM
alert(date.toLocaleTimeString("ko-KR"));
// → "오후 12:00:00"
// Arabic in most Arabic speaking countries uses real Arabic digits
alert(date.toLocaleTimeString("ar-EG"));
// → "٧:٠٠:٠٠ م"
// when requesting a language that may not be supported, such as
// Balinese, include a fallback language, in this case Indonesian
alert(date.toLocaleTimeString(["ban", "id"]));
// → "11.00.00"
例子:使用 options
参数
可以使用 options
参数来自定义 toLocaleTimeString
方法返回的字符串。
var date = new Date(Date.UTC(2012, 11, 20, 3, 0, 0)); // an application may want to use UTC and make that visible var options = {timeZone: "UTC", timeZoneName: "short"}; alert(date.toLocaleTimeString("en-US", options)); // → "3:00:00 AM GMT" // sometimes even the US needs 24-hour time alert(date.toLocaleTimeString("en-US", {hour12: false})); // → "19:00:00"
性能
当格式化大量日期时,最好创建一个 Intl.DateTimeFormat
对象,然后使用该对象 format
属性提供的方法。
规范
规范版本 | 规范状态 | 注解 |
---|---|---|
ECMAScript 3rd Edition. Implemented in JavaScript 1.0 | Standard | Initial definition. |
ECMAScript 5.1 (ECMA-262) Date.prototype.toLocaleTimeString |
Standard | |
ECMAScript 6 (ECMA-262) Date.prototype.toLocaleTimeString |
Release Candidate | |
ECMAScript Internationalization API Specification, 1st Edition | Standard | Defines locales and options arguments. |
浏览器兼容性
Feature | Chrome | Firefox (Gecko) | Internet Explorer | Opera | Safari |
---|---|---|---|---|---|
Basic support | (Yes) | (Yes) | (Yes) | (Yes) | (Yes) |
locales and options arguments |
24 | 29 (29) | 11 | 15 | 未实现 |
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 |