Internationalization

Number formatting

You can use the following Qt methods to print or parse numbers in different formats.

QLocale::toString(int n)
QLocale::toUInt(QString s)
QLocale::toDouble(QString s)

Here's an example that shows how to use the Qt number formatting API for a given locale. In this example, a random number is formatted using English-US, French, Hindi, Thai, and Arabic locales.

QLocale US(QLocale::English, QLocale::UnitedStates);
QLocale FRANCE(QLocale::French, QLocale::France);
QLocale INDIA(QLocale::Hindi, QLocale::India);
QLocale THAILAND(QLocale::Thai, QLocale::Thailand);
QLocale SAUDI(QLocale::Arabic, QLocale::SaudiArabia);
 
QList<QLocale> locales;
locales << US << FRANCE << INDIA << THAILAND << SAUDI;
 
QString text = qApp->translate("MyNumberFormatAppContext",
"Qt Number Format Example\n\n");

double randomNumber = -123456789.340;
foreach(QLocale currLocale , locales)

{
    text += QLocale::countryToString(currLocale.country())+ "\n" +
    qApp->translate("MyNumberFormatAppContext","Random Number: ") 
    + currLocale.toString(randomNumber,'f',3) + "\n\n";
  }

Here's the output:

Number format sample
Locale: French

Random Number: 12875
Decimal Point: ,
Negative Sign: -
Positive Sign +
Zero Digit: 0

Currency formatting

The following Qt method can be used for the localized representation of a currency value:

QLocale::toCurrencyString(qlonglong value, const QString & symbol = QString())

Here's an example that shows various currency formatting in English-US, Chinese, and Hindi locales.

QLocale US(QLocale::English, QLocale::UnitedStates);
QLocale CHINA(QLocale::Chinese, QLocale::China);
 
QList<QLocale> locales;
locales << US << CHINA;
 
float randomPrice = 14.99;
QString text = qApp->translate("MyCurrencyAppContext",
"Qt Currency Support Example\n\n");

foreach(QLocale currentLocale , locales){
    text +=  "\n" + QLocale::countryToString(currentLocale.country())+ "\n";
    foreach (QLocale currencyLocale, locales)
{
    //We recommend you use the standardized QLocale::CurrencyIsoCode 
    //instead of QLocale::CurrencySymbol. i.e. 14.99 USD vs $14.99
    text +=  currentLocale.toCurrencyString(randomPrice,
    currencyLocale.currencySymbol(QLocale::CurrencyIsoCode)) + "\n";
    }
}

Here's the output:

Qt currency support example

UnitedStates
USD14.99
CNY14.99

China
USD14.99
CNY14.99

Date and time formatting

The following Qt methods represent date and times in different locales:

QDate QLocale::toDate(const QString & string, FormatType format = LongFormat)

QTime QLocale::toTime(const QString & string, FormatType format = LongFormat)

QDateTime QLocale::toDateTime(const QString & string, 
    FormatType format = LongFormat)

QString QLocale::toString(const QDate & date, const QString & format)

QString QLocale::toString(const QDateTime & dateTime, 
    FormatType format = LongFormat)

Quotes

The following Qt method supports quoting strings based on the specified locale:

QString QLocale::quoteString(const QString & str, QuotationStyle style = 
    StandardQuotation) and its overloaded variant.

Lists

The following Qt method provides support for constructing a list of strings separated by a locale-based separator:

QString QLocale::createSeparatedList(const QStringList & list)

Calendar support

The following Qt methods provide support for formatting the day, week, and month for the specified locale. Only the Gregorian calendar is used in the calendar support.

QLocale::weekdays()
QLocale::firstDayOfWeek()
QLocale::dayName(int day, FormatType type = LongFormat)
QLocale::monthName(int month, FormatType type = LongFormat)

Measurement system

The following Qt methods provide support for handling measurement units (metric or imperial) of a specified locale:

QLocale::measurementSystem()

Formatting

Qt's QLocale offers mostly ShortFormat and LongFormat formatting types. The BlackBerry 10 OS further extends these formatting types to: date, time and percentage. The following methods return the localized format:

bb::utility::i18n::dateFormat(DateFormat::Type)
bb::utility::i18n::timeFormat(DateFormat::Type)
bb::utility::i18n::dateTimeFormat(DateFormat::Type)

The type of date format can be: short, medium, long, and full. Also, the overloads of the functions above accept QLocale as a first parameter. Here's some sample code that prints out ICU styled data and time formats in English-US, French, Arabic and Hindi locales.

QDateTime currTime = QDateTime::currentDateTime();
 
    QLocale US(QLocale::English, QLocale::UnitedStates);
    QLocale FRANCE(QLocale::French, QLocale::France);
    QLocale SAUDI(QLocale::Arabic, QLocale::SaudiArabia);
    QLocale INDIA(QLocale::Hindi, QLocale::India);
    QList<QLocale>locales;
    locales << US << FRANCE << SAUDI << INDIA;
 
    
QString RLM = QString::fromUtf8("\u200F");
text += qApp->translate("MyFormatAppContext" , 
    "\n\n DateTime Format Example \n\n");
 
foreach(QLocale currLocale , locales){
text += QLocale::countryToString(currLocale.country())+ "\n";
text += qApp->translate("MyFormatAppContext","SHORT: ") + RLM;
text += currLocale.toString( currTime, bb::utility::i18n::dateTimeFormat
    ( currLocale, bb::utility::i18n::DateFormat::Short ) ) + "\n";
text += qApp->translate("MyFormatAppContext","MEDIUM: ") + RLM;
text += currLocale.toString( currTime, bb::utility::i18n::dateTimeFormat
    ( currLocale, bb::utility::i18n::DateFormat::Medium ) ) + "\n";
text += qApp->translate("MyFormatAppContext","LONG: ") + RLM;
text += currLocale.toString( currTime, bb::utility::i18n::dateTimeFormat
    ( currLocale, bb::utility::i18n::DateFormat::Long ) ) + "\n";
text += qApp->translate("MyFormatAppContext","FULL: " ) + RLM;
text += currLocale.toString( currTime, bb::utility::i18n::dateTimeFormat
    ( currLocale, bb::utility::i18n::DateFormat::Full ) ) + "\n\n";}
}

Here's the output:

Collation support

The BlackBerry 10 OS uses QtCollator, which is part of Qt 5.0, as a basic string sorting and comparison engine in Cascades. Here are some important QtCollator methods:

For more information, see ICU Collator documentation.