const_iterator Class▲
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Header: const_iterator
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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: const_iterator is part of JSON Support in Qt
Detailed Description▲
QJsonObject::const_iterator allows you to iterate over a QJsonObject. If you want to modify the QJsonObject as you iterate over it, you must use QJsonObject::iterator instead. It is generally good practice to use QJsonObject::const_iterator on a non-const QJsonObject as well, unless you need to change the QJsonObject through the iterator. Const iterators are slightly faster and improve code readability.
The default QJsonObject::const_iterator constructor creates an uninitialized iterator. You must initialize it using a QJsonObject function like QJsonObject::constBegin(), QJsonObject::constEnd(), or QJsonObject::find() before you can start iterating.
Multiple iterators can be used on the same object. Existing iterators will however become dangling if the object gets modified.
See Also▲
Member Type Documentation▲
const_iterator::iterator_category▲
A synonym for std::random_access_iterator_tag indicating this iterator is a random-access iterator.
In Qt versions before 5.6, this was set by mistake to std::bidirectional_iterator_tag.
Member Function Documentation▲
bool const_iterator::operator==(const const_iterator &other) const▲
bool const_iterator::operator==(const iterator &other) const
Returns true if other points to the same item as this iterator; otherwise returns false.
See Also▲
See also operator!=()
bool const_iterator::operator!=(const const_iterator &other) const▲
bool const_iterator::operator!=(const iterator &other) const
Returns true if other points to a different item than this iterator; otherwise returns false.
See Also▲
See also operator==()
const_iterator::const_iterator()▲
Constructs an uninitialized iterator.
Functions like key(), value(), and operator++() must not be called on an uninitialized iterator. Use operator=() to assign a value to it before using it.
See Also▲
See also QJsonObject::constBegin(), QJsonObject::constEnd()
const_iterator::const_iterator(const iterator &other)▲
Constructs a copy of other.
QString const_iterator::key() const▲
QJsonValueConstRef const_iterator::value() const▲
const QJsonValueConstRef const_iterator::operator*() const▲
const_iterator const_iterator::operator+(qsizetype j) const▲
Returns an iterator to the item at j positions forward from this iterator. If j is negative, the iterator goes backward.
This operation can be slow for large j values.
See Also▲
See also operator-()
const_iterator &const_iterator::operator++()▲
The prefix ++ operator, ++i, advances the iterator to the next item in the object and returns an iterator to the new current item.
Calling this function on QJsonObject::end() leads to undefined results.
See Also▲
See also operator--()
const_iterator const_iterator::operator++(int)▲
This is an overloaded function.
The postfix ++ operator, i++, advances the iterator to the next item in the object and returns an iterator to the previously current item.
const_iterator &const_iterator::operator+=(qsizetype j)▲
Advances the iterator by j items. If j is negative, the iterator goes backward.
This operation can be slow for large j values.
See Also▲
See also operator-=(), operator+()
const_iterator const_iterator::operator-(qsizetype j) const▲
Returns an iterator to the item at j positions backward from this iterator. If j is negative, the iterator goes forward.
This operation can be slow for large j values.
See Also▲
See also operator+()
qsizetype const_iterator::operator-(const_iterator other) const▲
Returns the number of items between the item pointed to by other and the item pointed to by this iterator.
const_iterator &const_iterator::operator--()▲
The prefix -- operator, --i, makes the preceding item current and returns an iterator pointing to the new current item.
Calling this function on QJsonObject::begin() leads to undefined results.
See Also▲
See also operator++()
const_iterator const_iterator::operator--(int)▲
This is an overloaded function.
The postfix -- operator, i--, makes the preceding item current and returns an iterator pointing to the previously current item.
const_iterator &const_iterator::operator-=(qsizetype j)▲
Makes the iterator go back by j items. If j is negative, the iterator goes forward.
This operation can be slow for large j values.
See Also▲
See also operator+=(), operator-()
const QJsonValueConstRef *const_iterator::operator->() const▲
Returns a pointer to the current item.
bool const_iterator::operator<(const const_iterator &other) const▲
Returns true if the item pointed to by this iterator is less than the item pointed to by the other iterator.
bool const_iterator::operator<=(const const_iterator &other) const▲
Returns true if the item pointed to by this iterator is less than or equal to the item pointed to by the other iterator.
bool const_iterator::operator>(const const_iterator &other) const▲
Returns true if the item pointed to by this iterator is greater than the item pointed to by the other iterator.
bool const_iterator::operator>=(const const_iterator &other) const▲
Returns true if the item pointed to by this iterator is greater than or equal to the item pointed to by the other iterator.
QJsonValueConstRef const_iterator::operator[](qsizetype j) const▲
Returns the item at offset j from the item pointed to by this iterator (the item at position *this + j).
This function is provided to make QJsonObject iterators behave like C++ pointers.
See Also▲
See also operator+()