QAssociativeIterable Class▲
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Header: QAssociativeIterable
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Since: Qt 5.2
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qmake: QT += core
Detailed Description▲
This class allows several methods of accessing the elements of an associative container held within a QVariant. An instance of QAssociativeIterable can be extracted from a QVariant if it can be converted to a QVariantHash or QVariantMap.
QHash<int, QString> mapping;
mapping.insert(7, "Seven");
mapping.insert(11, "Eleven");
mapping.insert(42, "Forty-two");
QVariant variant = QVariant::fromValue(mapping);
if (variant.canConvert<QVariantHash>()) {
QAssociativeIterable iterable = variant.value<QAssociativeIterable>();
// Can use foreach over the values:
foreach (const QVariant &v, iterable) {
qDebug() << v;
}
// Can use C++11 range-for over the values:
for (const QVariant &v : iterable) {
qDebug() << v;
}
// Can use iterators:
QAssociativeIterable::const_iterator it = iterable.begin();
const QAssociativeIterable::const_iterator end = iterable.end();
for ( ; it != end; ++it) {
qDebug() << *it; // The current value
qDebug() << it.key();
qDebug() << it.value();
}
}The container itself is not copied before iterating over it.
See Also▲
See also QVariant
Member Function Documentation▲
QAssociativeIterable::const_iterator QAssociativeIterable::begin() const▲
Returns a QAssociativeIterable::const_iterator for the beginning of the container. This can be used in stl-style iteration.
See Also▲
See also end()
QAssociativeIterable::const_iterator QAssociativeIterable::end() const▲
Returns a QAssociativeIterable::const_iterator for the end of the container. This can be used in stl-style iteration.
See Also▲
See also begin()
[since 5.5] QAssociativeIterable::const_iterator QAssociativeIterable::find(const QVariant &key) const▲
Returns a QAssociativeIterable::const_iterator for the given key key in the container, if the types are convertible.
If the key is not found, returns end().
This can be used in stl-style iteration.
This function was introduced in Qt 5.5.
See Also▲
int QAssociativeIterable::size() const▲
Returns the number of elements in the container.