# Internationalization – i18n

> **NOTE**<br>
> - The initial APIs of this module are supported since API version 7. Newly added APIs will be marked with a superscript to indicate their earliest API version.
>
> - This module contains enhanced i18n APIs, which are not defined in ECMA 402.


## Modules to Import

```
import i18n from '@ohos.i18n';
```


## i18n.getDisplayLanguage

getDisplayLanguage(language: string, locale: string, sentenceCase?: boolean): string

Obtains the localized script for the specified language.

**System capability**: SystemCapability.Global.I18n

**Parameters**
| Name         | Type     | Mandatory  | Description              |
| ------------ | ------- | ---- | ---------------- |
| language     | string  | Yes   | Specified language.           |
| locale       | string  | Yes   | Locale ID.    |
| sentenceCase | boolean | No   | Whether to use sentence case for the localized script.|

**Return value**
| Type    | Description           |
| ------ | ------------- |
| string | Localized script for the specified language.|

**Example**
  ```
  i18n.getDisplayLanguage("zh", "en-GB", true);
  i18n.getDisplayLanguage("zh", "en-GB");
  ```


## i18n.getDisplayCountry

getDisplayCountry(country: string, locale: string, sentenceCase?: boolean): string

Obtains the localized script for the specified country.

**System capability**: SystemCapability.Global.I18n

**Parameters**
| Name         | Type     | Mandatory  | Description              |
| ------------ | ------- | ---- | ---------------- |
| country      | string  | Yes   | Specified country.           |
| locale       | string  | Yes   | Locale ID.    |
| sentenceCase | boolean | No   | Whether to use sentence case for the localized script.|

**Return value**
| Type    | Description           |
| ------ | ------------- |
| string | Localized script for the specified country.|

**Example**
  ```
  i18n.getDisplayCountry("zh-CN", "en-GB", true);
  i18n.getDisplayCountry("zh-CN", "en-GB");
  ```


## i18n.isRTL<sup>7+</sup>

isRTL(locale: string): boolean

Checks whether the localized script for the specified language is displayed from right to left.

**System capability**: SystemCapability.Global.I18n

**Parameters**
| Name   | Type    | Description     |
| ------ | ------ | ------- |
| locale | string | Locale ID.|

**Return value**
| Type     | Description                                      |
| ------- | ---------------------------------------- |
| boolean | Returns **true** if the localized script is displayed from right to left; returns **false** otherwise.|

**Example**
  ```
  i18n.isRTL("zh-CN");// Since Chinese is not written from right to left, false is returned.
  i18n.isRTL("ar-EG");// Since Arabic is written from right to left, true is returned.
  ```


## i18n.getSystemLanguage

getSystemLanguage(): string

Obtains the system language.

**System capability**: SystemCapability.Global.I18n

**Return value**
| Type    | Description     |
| ------ | ------- |
| string | System language ID.|

**Example**
  ```
  i18n.getSystemLanguage();
  ```


## i18n.setSystemLanguage

setSystemLanguage(language: string): boolean

Sets the system language.

**Permission required**: ohos.permission.UPDATE_CONFIGURATION

**System capability**: SystemCapability.Global.I18n

**System API**: This is a system API and cannot be called by third-party applications.

**Parameters**
| Name     | Type    | Description   |
| -------- | ------ | ----- |
| language | string | Language ID.|

**Return value**
| Type     | Description                                   |
| ------- | ------------------------------------- |
| boolean | Returns **true** if the operation is successful; returns **false** otherwise.|

**Example**
  ```
  i18n.setSystemLanguage('zh');
  ```


## i18n.getSystemLanguages

getSystemLanguages(): Array&lt;string&gt;

Obtains the list of system languages.

**System capability**: SystemCapability.Global.I18n

**System API**: This is a system API and cannot be called by third-party applications.

**Return value**
| Type                 | Description          |
| ------------------- | ------------ |
| Array&lt;string&gt; | List of the IDs of system languages.|

**Example**
  ```
  i18n.getSystemLanguages();
  ```


## i18n.getSystemCountries

getSystemCountries(language: string): Array&lt;string&gt;

Obtains the list of countries and regions supported for the specified language.

**System capability**: SystemCapability.Global.I18n

**System API**: This is a system API and cannot be called by third-party applications.

**Parameters**
| Name     | Type    | Description   |
| -------- | ------ | ----- |
| language | string | Language ID.|

**Return value**
| Type                 | Description          |
| ------------------- | ------------ |
| Array&lt;string&gt; | List of the IDs of the countries and regions supported for the specified language.|

**Example**
  ```
  i18n.getSystemCountries('zh');
  ```


## i18n.getSystemRegion

getSystemRegion(): string

Obtains the system region.

**System capability**: SystemCapability.Global.I18n

**Return value**
| Type    | Description     |
| ------ | ------- |
| string | System region ID.|

**Example**
  ```
  i18n.getSystemRegion();
  ```


## i18n.setSystemRegion

setSystemRegion(region: string): boolean

Sets the system region.

**Permission required**: ohos.permission.UPDATE_CONFIGURATION

**System capability**: SystemCapability.Global.I18n

**System API**: This is a system API and cannot be called by third-party applications.

**Parameters**
| Name   | Type    | Description   |
| ------ | ------ | ----- |
| region | string | Region ID.|

**Return value**
| Type     | Description                                   |
| ------- | ------------------------------------- |
| boolean | Returns **true** if the operation is successful; returns **false** otherwise.|

**Example**
  ```
  i18n.setSystemRegion('CN');
  ```


## i18n.getSystemLocale

getSystemLocale(): string

Obtains the system locale.

**System capability**: SystemCapability.Global.I18n

**Return value**
| Type    | Description     |
| ------ | ------- |
| string | System locale ID.|

**Example**
  ```
  i18n.getSystemLocale();
  ```


## i18n.setSystemLocale

setSystemLocale(locale: string): boolean

Sets the system locale.

**Permission required**: ohos.permission.UPDATE_CONFIGURATION

**System capability**: SystemCapability.Global.I18n

**System API**: This is a system API and cannot be called by third-party applications.

**Parameters**
| Name   | Type    | Description             |
| ------ | ------ | --------------- |
| locale | string | System locale ID, for example, **zh-CN**.|

**Return value**
| Type     | Description                                      |
| ------- | ---------------------------------------- |
| boolean | Returns **true** if the operation is successful; returns **false** otherwise.|

**Example**
  ```
  i18n.setSystemLocale('zh-CN');
  ```


## i18n.isSuggested

isSuggested(language: string, region?: string): boolean

Checks whether the system language matches the specified region.

**System capability**: SystemCapability.Global.I18n

**System API**: This is a system API and cannot be called by third-party applications.

**Parameters**
| Name     | Type    | Mandatory  | Description           |
| -------- | ------ | ---- | ------------- |
| language | string | Yes   | Valid language ID, for example, **zh**.|
| region   | string | No   | Valid region ID, for example, **CN**. |

**Return value**
| Type     | Description                                      |
| ------- | ---------------------------------------- |
| boolean | Returns **true** if the system language matches the specified region; returns **false** otherwise.|

**Example**
  ```
  i18n.isSuggested('zh', 'CN');
  ```


## i18n.getCalendar<sup>8+</sup>

getCalendar(locale: string, type? : string): Calendar

Obtains a **Calendar** object.

**System capability**: SystemCapability.Global.I18n

**Parameters**
| Name   | Type    | Mandatory  | Description                                      |
| ------ | ------ | ---- | ---------------------------------------- |
| locale | string | Yes   | Valid locale value, for example, **zh-Hans-CN**.                |
| type   | string | No   | Valid calendar type. Currently, the valid types are as follows: **buddhist**, **chinese**, **coptic**, **ethiopic**, **hebrew**, **gregory**, **indian**, **islamic\_civil**, **islamic\_tbla**, **islamic\_umalqura**, **japanese**, and **persian**. If this parameter is left unspecified, the default calendar type of the specified locale is used.|

**Return value**
| Type                    | Description   |
| ---------------------- | ----- |
| [Calendar](#calendar8) | **Calendar** object.|

**Example**
  ```
  i18n.getCalendar("zh-Hans", "gregory");
  ```


## Calendar<sup>8+</sup>


### setTime<sup>8+</sup>

setTime(date: Date): void

Sets the date for this **Calendar** object.

**System capability**: SystemCapability.Global.I18n

**Parameters**
| Name | Type  | Mandatory  | Description               |
| ---- | ---- | ---- | ----------------- |
| date | Date | Yes   | Date to be set for the **Calendar** object.|

**Example**
  ```
  var calendar = i18n.getCalendar("en-US", "gregory");
  var date = new Date(2021, 10, 7, 8, 0, 0, 0);
  calendar.setTime(date);
  ```


### setTime<sup>8+</sup>

setTime(time: number): void

Sets the date and time for this **Calendar** object. The value is represented by the number of milliseconds that have elapsed since the Unix epoch (00:00:00 UTC on January 1, 1970).

**System capability**: SystemCapability.Global.I18n

**Parameters**
| Name | Type    | Mandatory  | Description                                      |
| ---- | ------ | ---- | ---------------------------------------- |
| time | number | Yes   | Number of milliseconds that have elapsed since the Unix epoch.|

**Example**
  ```
  var calendar = i18n.getCalendar("en-US", "gregory");
  calendar.setTime(10540800000);
  ```


### set<sup>8+</sup>

set(year: number, month: number, date:number, hour?: number, minute?: number, second?: number): void

Sets the year, month, day, hour, minute, and second for this **Calendar** object.

**System capability**: SystemCapability.Global.I18n

**Parameters**
| Name   | Type    | Mandatory  | Description    |
| ------ | ------ | ---- | ------ |
| year   | number | Yes   | Year to set. |
| month  | number | Yes   | Month to set. |
| date   | number | Yes   | Day to set. |
| hour   | number | No   | Hour to set.|
| minute | number | No   | Minute to set.|
| second | number | No   | Second to set. |

**Example**
  ```
  var calendar = i18n.getCalendar("zh-Hans");
  calendar.set(2021, 10, 1, 8, 0, 0); // set time to 2021.10.1 08:00:00
  ```


### setTimeZone<sup>8+</sup>

setTimeZone(timezone: string): void

Sets the time zone of this **Calendar** object.

**System capability**: SystemCapability.Global.I18n

**Parameters**
| Name     | Type    | Mandatory  | Description                       |
| -------- | ------ | ---- | ------------------------- |
| timezone | string | Yes   | Time zone, for example, **Asia/Shanghai**.|

**Example**
  ```
  var calendar = i18n.getCalendar("zh-Hans");
  calendar.setTimeZone("Asia/Shanghai");
  ```


### getTimeZone<sup>8+</sup>

getTimeZone(): string

Obtains the time zone of this **Calendar** object.

**System capability**: SystemCapability.Global.I18n

**Return value**
| Type    | Description        |
| ------ | ---------- |
| string | Time zone of the **Calendar** object.|

**Example**
  ```
  var calendar = i18n.getCalendar("zh-Hans");
  calendar.setTimeZone("Asia/Shanghai");
  calendar.getTimeZone(); // Asia/Shanghai"
  ```


### getFirstDayOfWeek<sup>8+</sup>

getFirstDayOfWeek(): number

Obtains the start day of a week for this **Calendar** object.

**System capability**: SystemCapability.Global.I18n

**Return value**
| Type    | Description                   |
| ------ | --------------------- |
| number | Start day of a week. The value **1** indicates Sunday, and the value **7** indicates Saturday.|

**Example**
  ```
  var calendar = i18n.getCalendar("en-US", "gregory");
  calendar.getFirstDayOfWeek();
  ```


### setFirstDayOfWeek<sup>8+</sup>

setFirstDayOfWeek(value: number): void

Sets the start day of a week for this **Calendar** object.

**System capability**: SystemCapability.Global.I18n

**Parameters**
| Name  | Type    | Mandatory  | Description                   |
| ----- | ------ | ---- | --------------------- |
| value | number | No   | Start day of a week. The value **1** indicates Sunday, and the value **7** indicates Saturday.|

**Example**
  ```
  var calendar = i18n.getCalendar("zh-Hans");
  calendar.setFirstDayOfWeek(0);
  ```


### getMinimalDaysInFirstWeek<sup>8+</sup>

getMinimalDaysInFirstWeek(): number

Obtains the minimum number of days in the first week of a year.

**System capability**: SystemCapability.Global.I18n

**Return value**
| Type    | Description          |
| ------ | ------------ |
| number | Minimum number of days in the first week of a year.|

**Example**
  ```
  var calendar = i18n.getCalendar("zh-Hans");
  calendar.getMinimalDaysInFirstWeek();
  ```


### setMinimalDaysInFirstWeek<sup>8+</sup>

setMinimalDaysInFirstWeek(value: number): void

Sets the minimum number of days in the first week of a year.

**System capability**: SystemCapability.Global.I18n

**Parameters**
| Name  | Type    | Mandatory  | Description          |
| ----- | ------ | ---- | ------------ |
| value | number | No   | Minimum number of days in the first week of a year.|

**Example**
  ```
  var calendar = i18n.getCalendar("zh-Hans");
  calendar.setMinimalDaysInFirstWeek(3);
  ```


### get<sup>8+</sup>

get(field: string): number

Obtains the value of the specified field in the **Calendar** object.

**System capability**: SystemCapability.Global.I18n

**Parameters**
| Name  | Type    | Mandatory  | Description                                      |
| ----- | ------ | ---- | ---------------------------------------- |
| field | string | Yes   | Value of the specified field in the **Calendar** object. Currently, a valid field can be any of the following: **era**, **year**, **month**, **week\_of\_year**, **week\_of\_month**, **date**, **day\_of\_year**, **day\_of\_week**, **day\_of\_week\_in\_month**, **hour**, **hour\_of\_day**, **minute**, **second**, **millisecond**, **zone\_offset**, **dst\_offset**, **year\_woy**, **dow\_local**, **extended\_year**, **julian\_day**, **milliseconds\_in\_day**, **is\_leap\_month**.|

**Return value**
| Type    | Description                                      |
| ------ | ---------------------------------------- |
| number | Value of the specified field. For example, if the year in the internal date of this **Calendar** object is **1990**, the **get("year")** function will return **1990**.|

**Example**
  ```
  var calendar = i18n.getCalendar("zh-Hans");
  calendar.set(2021, 10, 1, 8, 0, 0); // set time to 2021.10.1 08:00:00
  calendar.get("hour_of_day"); // 8
  ```


### getDisplayName<sup>8+</sup>

getDisplayName(locale: string): string

Obtains the name of the **Calendar** object displayed for the specified locale.

**System capability**: SystemCapability.Global.I18n

**Parameters**
| Name   | Type    | Mandatory  | Description                                      |
| ------ | ------ | ---- | ---------------------------------------- |
| locale | string | Yes   | Locale for which the name of the **Calendar** object is displayed. For example, if **locale** is **en-US**, the name of the Buddhist calendar will be **Buddhist Calendar**.|

**Return value**
| Type    | Description                 |
| ------ | ------------------- |
| string | Name of the **Calendar** object displayed for the specified locale.|

**Example**
  ```
  var calendar = i18n.getCalendar("en-US", "buddhist");
  calendar.getDisplayName("zh"); // Obtain the name of the Buddhist calendar in zh.
  ```


### isWeekend<sup>8+</sup>

isWeekend(date?: Date): boolean

Checks whether the specified date in this **Calendar** object is a weekend.

**System capability**: SystemCapability.Global.I18n

**Parameters**
| Name | Type  | Mandatory  | Description                                      |
| ---- | ---- | ---- | ---------------------------------------- |
| date | Date | No   | Specified date in this **Calendar** object. If this parameter is left unspecified, the system checks whether the current date in the **Calendar** object is a weekend.|

**Return value**
| Type     | Description                                 |
| ------- | ----------------------------------- |
| boolean | Returns **true** if the date is a weekend; returns **false** if the date is a weekday.|

**Example**
  ```
  var calendar = i18n.getCalendar("zh-Hans");
  calendar.set(2021, 11, 11, 8, 0, 0); // set time to 2021.11.11 08:00:00
  calendar.isWeekend(); // false
  var date = new Date(2011, 11, 6, 9, 0, 0);
  calendar.isWeekend(date); // true
  ```


## PhoneNumberFormat<sup>8+</sup>


### constructor<sup>8+</sup>

constructor(country: string, options?: PhoneNumberFormatOptions)

Creates a **PhoneNumberFormat** object.

**System capability**: SystemCapability.Global.I18n

Parameters
| Name    | Type                                      | Mandatory  | Description              |
| ------- | ---------------------------------------- | ---- | ---------------- |
| country | string                                   | Yes   | Country or region to which the phone number to be formatted belongs.|
| options | [PhoneNumberFormatOptions](#phonenumberformatoptions8) | No   | Options of the **PhoneNumberFormat** object. |

**Example**
  ```
  var phoneNumberFormat= new i18n.PhoneNumberFormat("CN", {"type": "E164"});
  ```


### isValidNumber<sup>8+</sup>

isValidNumber(number: string): boolean

Checks whether the format of the specified phone number is valid.

**System capability**: SystemCapability.Global.I18n

**Parameters**
| Name   | Type    | Mandatory  | Description       |
| ------ | ------ | ---- | --------- |
| number | string | Yes   | Phone number to be checked.|

**Return value**
| Type     | Description                                   |
| ------- | ------------------------------------- |
| boolean | Returns **true** if the phone number format is valid; returns **false** otherwise.|

**Example**
  ```
  var phonenumberfmt = new i18n.PhoneNumberFormat("CN");
  phonenumberfmt.isValidNumber("15812312312");
  ```


### format<sup>8+</sup>

format(number: string): string

Formats a phone number.

**System capability**: SystemCapability.Global.I18n

**Parameters**
| Name   | Type    | Mandatory  | Description        |
| ------ | ------ | ---- | ---------- |
| number | string | Yes   | Phone number to be formatted.|

**Return value**
| Type    | Description        |
| ------ | ---------- |
| string | Formatted phone number.|

**Example**
  ```
  var phonenumberfmt = new i18n.PhoneNumberFormat("CN");
  phonenumberfmt.format("15812312312");
  ```


## PhoneNumberFormatOptions<sup>8+</sup>

Defines the options for this PhoneNumberFormat object.

**System capability**: SystemCapability.Global.I18n

| Name  | Type  | Readable  | Writable  | Description                                      |
| ---- | ------ | ---- | ---- | ---------------------------------------- |
| type | string | Yes   | Yes   | Format type of a phone number. The available options are as follows: E164,&nbsp;INTERNATIONAL,&nbsp;NATIONAL, and&nbsp;RFC3966.|


## UnitInfo<sup>8+</sup>

Defines the measurement unit information.

**System capability**: SystemCapability.Global.I18n

| Name           | Type  | Readable  | Writable  | Description                                      |
| ------------- | ------ | ---- | ---- | ---------------------------------------- |
| unit          | string | Yes   | Yes   | Name of the measurement unit, for example, **meter**, **inch**, or **cup**.|
| measureSystem | string | Yes   | Yes   | Measurement system. The value can be **SI**,&nbsp;**US**, or&nbsp;**UK**.|


## Util<sup>8+</sup>


### unitConvert<sup>8+</sup>

static unitConvert(fromUnit: UnitInfo, toUnit: UnitInfo, value: number, locale: string, style?: string): string

Converts one measurement unit into another and formats the unit based on the specified locale and style.

**System capability**: SystemCapability.Global.I18n

**Parameters**
| Name     | Type                    | Mandatory  | Description                                      |
| -------- | ---------------------- | ---- | ---------------------------------------- |
| fromUnit | [UnitInfo](#unitinfo8) | Yes   | Measurement unit to be converted.                                |
| toUnit   | [UnitInfo](#unitinfo8) | Yes   | Measurement unit to be converted to.                                |
| value    | number                 | Yes   | Value of the measurement unit to be converted.                            |
| locale   | string                 | Yes   | Locale used for formatting, for example, **zh-Hans-CN**.               |
| style    | string                 | No   | Style used for formatting. The value can be **long**, **short**, or **narrow**.|

**Return value**
| Type    | Description                     |
| ------ | ----------------------- |
| string | Character string obtained after formatting based on the measurement unit specified by **toUnit**.|

**Example**
  ```
  i18n.Util.unitConvert({unit: "cup", measureSystem: "US"}, {unit: "liter", measureSystem: "SI"}, 1000, "en-US", "long");
  ```


## getInstance<sup>8+</sup>

getInstance(locale?:string): IndexUtil

Creates an **IndexUtil** object.

**System capability**: SystemCapability.Global.I18n

**Parameters**
| Name   | Type    | Mandatory  | Description                          |
| ------ | ------ | ---- | ---------------------------- |
| locale | string | No   | A string containing locale information, including the language, optional script, and region.|

**Return value**
| Type                      | Description                   |
| ------------------------ | --------------------- |
| [IndexUtil](#indexutil8) | **IndexUtil** object mapping to the specified locale.|

**Example**
  ```
  var indexUtil= i18n.getInstance("zh-CN");
  ```


## IndexUtil<sup>8+</sup>


### getIndexList<sup>8+</sup>

getIndexList(): Array&lt;string&gt;

Obtains the index list for this **locale** object.

**System capability**: SystemCapability.Global.I18n

**Return value**
| Type                 | Description                |
| ------------------- | ------------------ |
| Array&lt;string&gt; | Index list for this **locale** object.|

**Example**
  ```
  var indexUtil = i18n.getInstance("zh-CN");
  var indexList = indexUtil.getIndexList();
  ```


### addLocale<sup>8+</sup>

addLocale(locale: string): void

Adds the index of the new **locale** object to the index list.

**System capability**: SystemCapability.Global.I18n

**Parameters**
| Name   | Type    | Mandatory  | Description                          |
| ------ | ------ | ---- | ---------------------------- |
| locale | string | Yes   | A string containing locale information, including the language, optional script, and region.|

**Example**
  ```
  var indexUtil = i18n.getInstance("zh-CN");
  indexUtil.addLocale("en-US");
  ```


### getIndex<sup>8+</sup>

getIndex(text: string): string

Obtains the index of a text object.

**System capability**: SystemCapability.Global.I18n

**Parameters**
| Name | Type    | Mandatory  | Description          |
| ---- | ------ | ---- | ------------ |
| text | string | Yes   | **text** object whose index is to be obtained.|

**Return value**
| Type    | Description         |
| ------ | ----------- |
| string | Index of the **text** object.|

**Example**
  ```
  var indexUtil= i18n.getInstance("zh-CN");
  indexUtil.getIndex("hi"); // Return h.
  ```


## Character<sup>8+</sup>


### isDigit<sup>8+</sup>

static isDigit(char: string): boolean

Checks whether the input character string is composed of digits.

**System capability**: SystemCapability.Global.I18n

**Parameters**
| Name | Type    | Mandatory  | Description   |
| ---- | ------ | ---- | ----- |
| char | string | Yes   | Input character.|

**Return value**
| Type     | Description                                  |
| ------- | ------------------------------------ |
| boolean | Returns **true** if the input character is a digit; returns **false** otherwise.|

**Example**
  ```
  var isdigit = i18n.Character.isDigit("1"); // Return true.
  ```


### isSpaceChar<sup>8+</sup>

static isSpaceChar(char: string): boolean

Checks whether the input character is a space.

**System capability**: SystemCapability.Global.I18n

**Parameters**
| Name | Type    | Mandatory  | Description   |
| ---- | ------ | ---- | ----- |
| char | string | Yes   | Input character.|

**Return value**
| Type     | Description                                    |
| ------- | -------------------------------------- |
| boolean | Returns **true** if the input character is a space; returns **false** otherwise.|

**Example**
  ```
  var isspacechar = i18n.Character.isSpaceChar("a"); // Return false.
  ```


### isWhitespace<sup>8+</sup>

static isWhitespace(char: string): boolean

Checks whether the input character is a white space.

**System capability**: SystemCapability.Global.I18n

**Parameters**
| Name | Type    | Mandatory  | Description   |
| ---- | ------ | ---- | ----- |
| char | string | Yes   | Input character.|

**Return value**
| Type     | Description                                    |
| ------- | -------------------------------------- |
| boolean | Returns **true** if the input character is a white space; returns **false** otherwise.|

**Example**
  ```
  var isspacechar = i18n.Character.isSpaceChar("a"); // Return false.
  ```


### isRTL<sup>8+</sup>

static isRTL(char: string): boolean

Checks whether the input character is of the right to left (RTL) language.

**System capability**: SystemCapability.Global.I18n

**Parameters**
| Name | Type    | Mandatory  | Description   |
| ---- | ------ | ---- | ----- |
| char | string | Yes   | Input character.|

**Return value**
| Type     | Description                                      |
| ------- | ---------------------------------------- |
| boolean | Returns **true** if the input character is of the RTL language; returns **false** otherwise.|

**Example**
  ```
  var isrtl = i18n.Character.isRTL("a"); // Return false.
  ```


### isIdeograph<sup>8+</sup>

static isIdeograph(char: string): boolean

Checks whether the input character is an ideographic character.

**System capability**: SystemCapability.Global.I18n

**Parameters**
| Name | Type    | Mandatory  | Description   |
| ---- | ------ | ---- | ----- |
| char | string | Yes   | Input character.|

**Return value**
| Type     | Description                                      |
| ------- | ---------------------------------------- |
| boolean | Returns **true** if the input character is an ideographic character; returns **false** otherwise.|

**Example**
  ```
  var isideograph = i18n.Character.isIdeograph("a"); // Return false.
  ```


### isLetter<sup>8+</sup>

static isLetter(char: string): boolean

Checks whether the input character is a letter.

**System capability**: SystemCapability.Global.I18n

**Parameters**
| Name | Type    | Mandatory  | Description   |
| ---- | ------ | ---- | ----- |
| char | string | Yes   | Input character.|

**Return value**
| Type     | Description                                  |
| ------- | ------------------------------------ |
| boolean | Returns **true** if the input character is a letter; returns **false** otherwise.|

**Example**
  ```
  var isletter = i18n.Character.isLetter("a"); // Return true.
  ```


### isLowerCase<sup>8+</sup>

static isLowerCase(char: string): boolean

Checks whether the input character is a lowercase letter.

**System capability**: SystemCapability.Global.I18n

**Parameters**
| Name | Type    | Mandatory  | Description   |
| ---- | ------ | ---- | ----- |
| char | string | Yes   | Input character.|

**Return value**
| Type     | Description                                      |
| ------- | ---------------------------------------- |
| boolean | Returns **true** if the input character is a lowercase letter; returns **false** otherwise.|

**Example**
  ```
  var islowercase = i18n.Character.isLowerCase("a"); // Return true.
  ```


### isUpperCase<sup>8+</sup>

static isUpperCase(char: string): boolean

Checks whether the input character is an uppercase letter.

**System capability**: SystemCapability.Global.I18n

**Parameters**
| Name | Type    | Mandatory  | Description   |
| ---- | ------ | ---- | ----- |
| char | string | Yes   | Input character.|

**Return value**
| Type     | Description                                      |
| ------- | ---------------------------------------- |
| boolean | Returns **true** if the input character is an uppercase letter; returns **false** otherwise.|

**Example**
  ```
  var isuppercase = i18n.Character.isUpperCase("a"); // Return false.
  ```


### getType<sup>8+</sup>

static getType(char: string): string

Obtains the type of the input character string.

**System capability**: SystemCapability.Global.I18n

**Parameters**
| Name | Type    | Mandatory  | Description   |
| ---- | ------ | ---- | ----- |
| char | string | Yes   | Input character.|

**Return value**
| Type    | Description         |
| ------ | ----------- |
| string | Type of the input character.|

**Example**
  ```
  var type = i18n.Character.getType("a");
  ```


## i18n.getLineInstance<sup>8+</sup>

getLineInstance(locale: string): BreakIterator

Obtains a [BreakIterator](#breakiterator8) object for text segmentation.

**System capability**: SystemCapability.Global.I18n

**Parameters**
| Name   | Type    | Mandatory  | Description                                      |
| ------ | ------ | ---- | ---------------------------------------- |
| locale | string | Yes   | Valid locale value, for example, **zh-Hans-CN**. The [BreakIterator](#breakiterator8) object segments text according to the rules of the specified locale.|

**Return value**
| Type                              | Description         |
| -------------------------------- | ----------- |
| [BreakIterator](#breakiterator8) | [BreakIterator](#breakiterator8) object used for text segmentation.|

**Example**
  ```
  var iterator = i18n.getLineInstance("en");
  ```


## BreakIterator<sup>8+</sup>


### setLineBreakText<sup>8+</sup>

setLineBreakText(text: string): void

Sets the text to be processed by the [BreakIterator](#breakiterator8) object.

**System capability**: SystemCapability.Global.I18n

**Parameters**
| Name | Type    | Mandatory  | Description                     |
| ---- | ------ | ---- | ----------------------- |
| text | string | Yes   | Text to be processed by the **BreakIterator** object.|

**Example**
  ```
  var iterator = i18n.getLineInstance("en");
  iterator.setLineBreakText("Apple is my favorite fruit.");
  ```


### getLineBreakText<sup>8+</sup>

getLineBreakText(): string

Obtains the text being processed by the [BreakIterator](#breakiterator8) object.

**System capability**: SystemCapability.Global.I18n

**Return value**
| Type    | Description                    |
| ------ | ---------------------- |
| string | Text being processed by the **BreakIterator** object.|

**Example**
  ```
  var iterator = i18n.getLineInstance("en");
  iterator.setLineBreakText("Apple is my favorite fruit.");
  iterator.getLineBreakText(); // Apple is my favorite fruit.
  ```


### current<sup>8+</sup>

current(): number

Obtains the position of the [BreakIterator](#breakiterator8) object in the text being processed.

**System capability**: SystemCapability.Global.I18n

**Return value**
| Type    | Description                         |
| ------ | --------------------------- |
| number | Position of the **BreakIterator** object in the text being processed.|

**Example**
  ```
  var iterator = i18n.getLineInstance("en");
  iterator.setLineBreakText("Apple is my favorite fruit.");
  iterator.current(); // 0
  ```


### first<sup>8+</sup>

first(): number

Puts the [BreakIterator](#breakiterator8) object to the first text boundary, which is always at the beginning of the processed text.

**System capability**: SystemCapability.Global.I18n

**Return value**
| Type    | Description               |
| ------ | ----------------- |
| number | Offset to the first text boundary of the processed text.|

**Example**
  ```
  var iterator = i18n.getLineInstance("en");
  iterator.setLineBreakText("Apple is my favorite fruit.");
  iterator.first(); // 0
  ```


### last<sup>8+</sup>

last(): number

Puts the [BreakIterator](#breakiterator8) object to the last text boundary, which is always the next position after the end of the processed text.

**System capability**: SystemCapability.Global.I18n

**Return value**
| Type    | Description                |
| ------ | ------------------ |
| number | Offset of the last text boundary of the processed text.|

**Example**
  ```
  var iterator = i18n.getLineInstance("en");
  iterator.setLineBreakText("Apple is my favorite fruit.");
  iterator.last(); // 27
  ```


### next<sup>8+</sup>

next(index?: number): number

Moves the [BreakIterator](#breakiterator8) object backward by the specified number of text boundaries if the specified index is a positive number. If the index is a negative number, the [BreakIterator](#breakiterator8) object will be moved forward by the corresponding number of text boundaries. If no index is specified, the index will be treated as **1**.

**System capability**: SystemCapability.Global.I18n

**Parameters**
| Name  | Type    | Mandatory  | Description                                      |
| ----- | ------ | ---- | ---------------------------------------- |
| index | number | No   | Number of text boundaries by which the [BreakIterator](#breakiterator8) object is moved. A positive value indicates that the text boundary is moved backward, and a negative value indicates the opposite. If no index is specified, the index will be treated as **1**.|

**Return value**
| Type    | Description                                      |
| ------ | ---------------------------------------- |
| number | Position of the [BreakIterator](#breakiterator8) object in the text after it is moved by the specified number of text boundaries. The value **-1** is returned if the position of the [BreakIterator](#breakiterator8) object is outside of the processed text after it is moved by the specified number of text boundaries.|

**Example**
  ```
  var iterator = i18n.getLineInstance("en");
  iterator.setLineBreakText("Apple is my favorite fruit.");
  iterator.first(); // 0
  iterator.next(); // 6
  iterator.next(10); // -1
  ```


### previous<sup>8+</sup>

previous(): number

Moves the [BreakIterator](#breakiterator8) object to the previous text boundary.

**System capability**: SystemCapability.Global.I18n

**Return value**
| Type    | Description                                      |
| ------ | ---------------------------------------- |
| number | Position of the [BreakIterator](#breakiterator8) object in the text after it is moved to the previous text boundary. The value **-1** is returned if the position of the [BreakIterator](#breakiterator8) object is outside of the processed text after it is moved by the specified number of text boundaries.|

**Example**
  ```
  var iterator = i18n.getLineInstance("en");
  iterator.setLineBreakText("Apple is my favorite fruit.");
  iterator.first(); // 0
  iterator.next(3); // 12
  iterator.previous(); // 9
  ```


### following<sup>8+</sup>

following(offset: number): number

Moves the [BreakIterator](#breakiterator8) object to the text boundary after the position specified by the offset. Position of the [BreakIterator](#breakiterator8) object after it is moved to the text boundary after the position specified by the offset.

**System capability**: SystemCapability.Global.I18n

**Parameters**
| Name   | Type    | Mandatory  | Description                                      |
| ------ | ------ | ---- | ---------------------------------------- |
| offset | number | Yes   | Offset to the position before the text boundary to which the [BreakIterator](#breakiterator8) object is moved.|

**Return value**
| Type    | Description                                      |
| ------ | ---------------------------------------- |
| number | The value **-1** is returned if the text boundary to which the [BreakIterator](#breakiterator8) object is moved is outside of the processed text.|

**Example**
  ```
  var iterator = i18n.getLineInstance("en");
  iterator.setLineBreakText("Apple is my favorite fruit.");
  iterator.following(0); // 6
  iterator.following(100); // -1
  iterator.current(); // 27
  ```


### isBoundary<sup>8+</sup>

isBoundary(offset: number): boolean

Checks whether the position specified by the offset is a text boundary. If **true** is returned, the [BreakIterator](#breakiterator8) object is moved to the position specified by the offset. If **false** is returned, the [BreakIterator](#breakiterator8) object is moved to the text boundary after the position specified by the offset, which is equivalent to calling [following](#following8)(offset).

**System capability**: SystemCapability.Global.I18n

**Parameters**
| Name   | Type    | Mandatory  | Description         |
| ------ | ------ | ---- | ----------- |
| offset | number | Yes   | Position to check.|

**Return value**
| Type     | Description                             |
| ------- | ------------------------------- |
| boolean | Returns **true** if the position specified by the offset is a text boundary; returns **false** otherwise.|

**Example**
  ```
  var iterator = i18n.getLineInstance("en");
  iterator.setLineBreakText("Apple is my favorite fruit.");
  iterator.isBoundary(0); // true;
  iterator.isBoundary(5); // false;
  ```


## i18n.is24HourClock<sup>7+</sup>

is24HourClock(): boolean

Checks whether the 24-hour clock is used.

**System capability**: SystemCapability.Global.I18n

**Return value**
| Type     | Description                                      |
| ------- | ---------------------------------------- |
| boolean | Returns **true** if the 24-hour clock is used; returns **false** otherwise.|

**Example**
  ```
  var is24HourClock = i18n.is24HourClock();
  ```


## i18n.set24HourClock<sup>7+</sup>

set24HourClock(option: boolean): boolean

Sets the 24-hour clock.

**Permission required**: ohos.permission.UPDATE_CONFIGURATION

**System capability**: SystemCapability.Global.I18n

**Parameters**
| Name   | Type     | Mandatory  | Description                                      |
| ------ | ------- | ---- | ---------------------------------------- |
| option | boolean | Yes   | Whether to enable the 24-hour clock. The value **true** means to enable the 24-hour clock, and the value **false** means the opposite.|

**Return value**
| Type     | Description                           |
| ------- | ----------------------------- |
| boolean | Returns **true** if the 24-hour clock is enabled; returns **false** otherwise.|

**Example**
  ```
  // Set the system time to the 24-hour clock.
  var success = i18n.set24HourClock(true);
  ```


## i18n.addPreferredLanguage<sup>8+</sup>

addPreferredLanguage(language: string, index?: number): boolean

Adds a preferred language to the specified position on the preferred language list.

**Permission required**: ohos.permission.UPDATE_CONFIGURATION

**System capability**: SystemCapability.Global.I18n

**Parameters**
| Name     | Type    | Mandatory  | Description        |
| -------- | ------ | ---- | ---------- |
| language | string | Yes   | Preferred language to add. |
| index    | number | No   | Position to which the preferred language is added.|

**Return value**
| Type     | Description                           |
| ------- | ----------------------------- |
| boolean | Returns **true** if the preferred language is successfully added; returns **false** otherwise.|

**Example**
  ```
  // Add zh-CN to the preferred language list.
  var language = 'zh-CN';
  var index = 0;
  var success = i18n.addPreferredLanguage(language, index);
  ```


## i18n.removePreferredLanguage<sup>8+</sup>

removePreferredLanguage(index: number): boolean

Deletes a preferred language from the specified position on the preferred language list.

**Permission required**: ohos.permission.UPDATE_CONFIGURATION

**System capability**: SystemCapability.Global.I18n

**Parameters**
| Name  | Type    | Mandatory  | Description                   |
| ----- | ------ | ---- | --------------------- |
| index | number | Yes   | Position of the preferred language to delete.|

**Return value**
| Type     | Description                           |
| ------- | ----------------------------- |
| boolean | Returns **true** if the preferred language is deleted; returns **false** otherwise.|

**Example**
  ```
  // Delete the first preferred language from the preferred language list.
  var index = 0;
  var success = i18n.removePreferredLanguage(index);
  ```


## i18n.getPreferredLanguageList<sup>8+</sup>

getPreferredLanguageList(): Array&lt;string&gt;

Obtains the list of preferred languages.

**System capability**: SystemCapability.Global.I18n

**Return value**
| Type                 | Description       |
| ------------------- | --------- |
| Array&lt;string&gt; | List of preferred languages.|

**Example**
  ```
  var preferredLanguageList = i18n.getPreferredLanguageList();
  ```


## i18n.getFirstPreferredLanguage<sup>8+</sup>

getFirstPreferredLanguage(): string

Obtains the first language in the preferred language list.

**System capability**: SystemCapability.Global.I18n

**Return value**
| Type    | Description            |
| ------ | -------------- |
| string | First language in the preferred language list.|

**Example**
  ```
  var firstPreferredLanguage = i18n.getFirstPreferredLanguage();
  ```


## i18n.getAppPreferredLanguage<sup>9+</sup>

getAppPreferredLanguage(): string

Obtains the preferred language of an application.

**System capability**: SystemCapability.Global.I18n

**Return value**
| Type    | Description            |
| ------ | -------------- |
| string | Preferred language of the application.|

**Example**
  ```
  var appPreferredLanguage = i18n.getAppPreferredLanguage();
  ```


## i18n.getTimeZone<sup>7+</sup>

getTimeZone(zoneID?: string): TimeZone

Obtains the **TimeZone** object corresponding to the specified time zone ID.

**System capability**: SystemCapability.Global.I18n

**Parameters**
| Name   | Type    | Mandatory  | Description   |
| ------ | ------ | ---- | ----- |
| zondID | string | No   | Time zone ID.|

**Return value**
| Type      | Description          |
| -------- | ------------ |
| TimeZone | **TimeZone** object corresponding to the time zone ID.|

**Example**
  ```
  var timezone = i18n.getTimeZone();
  ```


## RelativeTimeFormat<sup>8+</sup>


### getID<sup>8+</sup>

getID(): string

Obtains the ID of the specified **TimeZone** object.

**System capability**: SystemCapability.Global.I18n

**Return value**
| Type    | Description          |
| ------ | ------------ |
| string | Time zone ID corresponding to the **TimeZone** object.|

**Example**
  ```
  var timezone = i18n.getTimeZone();
  timezone.getID();
  ```


### getDisplayName<sup>8+</sup>

getDisplayName(locale?: string, isDST?: boolean): string

Obtains the representation of a **TimeZone** object in the specified locale.

**System capability**: SystemCapability.Global.I18n

**Parameters**
| Name   | Type     | Mandatory  | Description                  |
| ------ | ------- | ---- | -------------------- |
| locale | string  | No   | System locale ID.               |
| isDST  | boolean | No   | Whether to consider DST when obtaining the representation of the **TimeZone** object.|

**Return value**
| Type    | Description           |
| ------ | ------------- |
| string | Representation of the **TimeZone** object in the specified locale.|

**Example**
  ```
  var timezone = i18n.getTimeZone();
  timezone.getDisplayName("zh-CN", false);
  ```


### getRawOffset<sup>8+</sup>

getRawOffset(): number

Obtains the offset between the time zone represented by a **TimeZone** object and the UTC time zone.

**System capability**: SystemCapability.Global.I18n

**Return value**
| Type    | Description                 |
| ------ | ------------------- |
| number | Offset between the time zone represented by the **TimeZone** object and the UTC time zone.|

**Example**
  ```
  var timezone = i18n.getTimeZone();
  timezone.getRawOffset();
  ```


### getOffset<sup>8+</sup>

getOffset(date?: number): number

Obtains the offset between the time zone represented by a **TimeZone** object and the UTC time zone at a certain time point.

**System capability**: SystemCapability.Global.I18n

**Return value**
| Type    | Description                     |
| ------ | ----------------------- |
| number | Offset between the time zone represented by the **TimeZone** object and the UTC time zone at a certain time point.|

**Example**
  ```
  var timezone = i18n.getTimeZone();
  timezone.getOffset(1234567890);
  ```