QCollator Class▲
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Header: QCollator
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Since: Qt 5.2
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CMake:
find_package(Qt6 REQUIRED COMPONENTS Core)
target_link_libraries(mytarget PRIVATE Qt6::Core)
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qmake: QT += core
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Group: QCollator is part of i18n, string-processing, Implicitly Shared Classes
Detailed Description▲
QCollator is initialized with a QLocale. It can then be used to compare and sort strings in using the ordering appropriate to the locale.
A QCollator object can be used together with template-based sorting algorithms, such as std::sort(), to sort a list with QString entries.
QStringList sortedStrings(QStringList seq)
{
QCollator order;
std::sort(seq.begin(), seq.end(), order);
return seq;
}In addition to the locale, several optional flags can be set that influence the result of the collation.
On Linux, Qt is normally compiled to use ICU. When it isn't, all options are ignored and the only supported locales are the system default (that setlocale(LC_COLLATE, nullptr) would report) and the "C" locale.
Member Function Documentation▲
[since 5.13] QCollator::QCollator()▲
Constructs a QCollator using the default locale's collation locale.
The system locale, when used as default locale, may have a collation locale other than itself (e.g. on Unix, if LC_COLLATE is set differently to LANG in the environment). All other locales are their own collation locales.
This function was introduced in Qt 5.13.
See Also▲
See also setLocale(), QLocale::collation(), QLocale::setDefault()
[explicit] QCollator::QCollator(const QLocale &locale)▲
QCollator::QCollator(const QCollator &other)▲
Creates a copy of other.
QCollator::QCollator(QCollator &&other)▲
Move constructor. Moves from other into this collator.
Note that a moved-from QCollator can only be destroyed or assigned to. The effect of calling other functions than the destructor or one of the assignment operators is undefined.
QCollator::~QCollator()▲
Destroys this collator.
Qt::CaseSensitivity QCollator::caseSensitivity() const▲
Returns case sensitivity of the collator.
This defaults to case-sensitive until set.
In the C locale, when case-sensitive, all lower-case letters sort after all upper-case letters, where most locales sort each lower-case letter either immediately before or immediately after its upper-case partner. Thus "Zap" sorts before "ape" in the C locale but after in most others.
See Also▲
See also setCaseSensitivity()
[since 5.13] int QCollator::compare(QStringView s1, QStringView s2) const▲
Compares s1 with s2.
Returns an integer less than, equal to, or greater than zero depending on whether s1 sorts before, with or after s2.
This function was introduced in Qt 5.13.
[since 5.2] int QCollator::compare(const QString &s1, const QString &s2) const▲
This is an overloaded function.
This function was introduced in Qt 5.2.
[since 5.2] int QCollator::compare(const QChar *s1, qsizetype len1, const QChar *s2, qsizetype len2) const▲
This is an overloaded function.
Compares s1 with s2. len1 and len2 specify the lengths of the QChar arrays pointed to by s1 and s2.
Returns an integer less than, equal to, or greater than zero depending on whether s1 sorts before, with or after s2.
In Qt versions prior to 6.4, the length arguments were of type int, not qsizetype.
This function was introduced in Qt 5.2.
[static, since 6.3] int QCollator::defaultCompare(QStringView s1, QStringView s2)▲
Compares the strings s1 and s2, returning their sorting order. This function performs the same operation as compare() on a default-constructed QCollator object.
This function was introduced in Qt 6.3.
See Also▲
See also compare(), defaultSortKey()
[static, since 6.3] QCollatorSortKey QCollator::defaultSortKey(QStringView key)▲
Returns the sort key for the string key. This function performs the same operation as sortKey() on a default-constructed QCollator object.
This function was introduced in Qt 6.3.
See Also▲
See also sortKey(), defaultCompare()
bool QCollator::ignorePunctuation() const▲
Returns whether punctuation and symbols are ignored when collating.
When true, strings are compared as if all punctuation and symbols were removed from each string.
See Also▲
See also setIgnorePunctuation()
QLocale QCollator::locale() const▲
Returns the locale of the collator.
Unless supplied to the constructor or by calling setLocale(), the system's default collation locale is used.
See Also▲
See also setLocale(), QLocale::collation()
bool QCollator::numericMode() const▲
Returns true if numeric sorting is enabled, false otherwise.
When true, numerals are recognized as numbers and sorted in arithmetic order; for example, 100 sortes after 99. When false, numbers are sorted in lexical order, so that 100 sorts before 99 (because 1 is before 9). By default, this option is disabled.
See Also▲
See also setNumericMode()
void QCollator::setCaseSensitivity(Qt::CaseSensitivity cs)▲
void QCollator::setIgnorePunctuation(bool on)▲
Ignores punctuation and symbols if on is true, attends to them if false.
See Also▲
See also ignorePunctuation()
void QCollator::setLocale(const QLocale &locale)▲
void QCollator::setNumericMode(bool on)▲
QCollatorSortKey QCollator::sortKey(const QString &string) const▲
Returns a sortKey for string.
Creating the sort key is usually somewhat slower, than using the compare() methods directly. But if the string is compared repeatedly (e.g. when sorting a whole list of strings), it's usually faster to create the sort keys for each string and then sort using the keys.
Not supported with the C (a.k.a. POSIX) locale on Darwin.
void QCollator::swap(QCollator &other)▲
Swaps this collator with other. This function is very fast and never fails.
[since 5.13] bool QCollator::operator()(QStringView s1, QStringView s2) const▲
A QCollator can be used as the comparison function of a sorting algorithm. It returns true if s1 sorts before s2, otherwise false.
This function was introduced in Qt 5.13.
See Also▲
See also compare()
[since 5.2] bool QCollator::operator()(const QString &s1, const QString &s2) const▲
This is an overloaded function.
This function was introduced in Qt 5.2.
QCollator &QCollator::operator=(const QCollator &other)▲
Assigns other to this collator.
QCollator &QCollator::operator=(QCollator &&other)▲
Move-assigns from other to this collator.
Note that a moved-from QCollator can only be destroyed or assigned to. The effect of calling other functions than the destructor or one of the assignment operators is undefined.