const_iterator Class
(QJsonArray::const_iterator)The QJsonArray::const_iterator class provides an STL-style const iterator for QJsonArray. More...
| Header: | #include <const_iterator> |
| qmake: | QT += core |
Public Types
| typedef | iterator_category |
| typedef | pointer |
Public Functions
| const_iterator() | |
| const_iterator(const const_iterator & other) | |
| const_iterator(const iterator & other) | |
| bool | operator!=(const const_iterator & other) const |
| QJsonValue | operator*() const |
| const_iterator | operator+(int j) const |
| const_iterator & | operator++() |
| const_iterator | operator++(int) |
| const_iterator & | operator+=(int j) |
| const_iterator | operator-(int j) const |
| int | operator-(const_iterator other) const |
| const_iterator & | operator--() |
| const_iterator | operator--(int) |
| const_iterator & | operator-=(int j) |
| QJsonValue * | operator->() const |
| bool | operator<(const const_iterator & other) const |
| bool | operator<=(const const_iterator & other) const |
| bool | operator==(const const_iterator & other) const |
| bool | operator>(const const_iterator & other) const |
| bool | operator>=(const const_iterator & other) const |
| QJsonValue | operator[](int j) const |
Detailed Description
The QJsonArray::const_iterator class provides an STL-style const iterator for QJsonArray.
QJsonArray::const_iterator allows you to iterate over a QJsonArray. If you want to modify the QJsonArray as you iterate over it, use QJsonArray::iterator instead. It is generally a good practice to use QJsonArray::const_iterator on a non-const QJsonArray as well, unless you need to change the QJsonArray through the iterator. Const iterators are slightly faster and improves code readability.
The default QJsonArray::const_iterator constructor creates an uninitialized iterator. You must initialize it using a QJsonArray function like QJsonArray::constBegin(), QJsonArray::constEnd(), or QJsonArray::insert() before you can start iterating.
Most QJsonArray functions accept an integer index rather than an iterator. For that reason, iterators are rarely useful in connection with QJsonArray. One place where STL-style iterators do make sense is as arguments to generic algorithms.
Multiple iterators can be used on the same array. However, be aware that any non-const function call performed on the QJsonArray will render all existing iterators undefined.
See also QJsonArray::iterator.
Member Type Documentation
typedef const_iterator::iterator_category
A synonym for std::random_access_iterator_tag indicating this iterator is a random access iterator.
typedef const_iterator::pointer
Member Function Documentation
const_iterator::const_iterator()
Constructs an uninitialized iterator.
Functions like operator*() and operator++() should not be called on an uninitialized iterator. Use operator=() to assign a value to it before using it.
See also QJsonArray::constBegin() and QJsonArray::constEnd().
const_iterator::const_iterator(const const_iterator & other)
Constructs a copy of other.
const_iterator::const_iterator(const iterator & other)
Constructs a copy of other.
bool const_iterator::operator!=(const const_iterator & other) const
Returns true if other points to a different item than this iterator; otherwise returns false.
See also operator==().
QJsonValue const_iterator::operator*() const
Returns the current item.
const_iterator const_iterator::operator+(int j) const
Returns an iterator to the item at j positions forward from this iterator. If j is negative, the iterator goes backward.
See also operator-() and operator+=().
const_iterator & const_iterator::operator++()
The prefix ++ operator, ++it, advances the iterator to the next item in the array and returns an iterator to the new current item.
Calling this function on QJsonArray::end() leads to undefined results.
See also operator--().
const_iterator const_iterator::operator++(int)
This is an overloaded function.
The postfix ++ operator, it++, advances the iterator to the next item in the array and returns an iterator to the previously current item.
const_iterator & const_iterator::operator+=(int j)
Advances the iterator by j items. If j is negative, the iterator goes backward.
See also operator-=() and operator+().
const_iterator const_iterator::operator-(int j) const
Returns an iterator to the item at j positions backward from this iterator. If j is negative, the iterator goes forward.
See also operator+() and operator-=().
int 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, --it, makes the preceding item current and returns an iterator to the new current item.
Calling this function on QJsonArray::begin() leads to undefined results.
See also operator++().
const_iterator const_iterator::operator--(int)
This is an overloaded function.
The postfix -- operator, it--, makes the preceding item current and returns an iterator to the previously current item.
const_iterator & const_iterator::operator-=(int j)
Makes the iterator go back by j items. If j is negative, the iterator goes forward.
See also operator+=() and operator-().
QJsonValue * 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 other points to the same item as this iterator; otherwise returns false.
See also operator!=().
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.
QJsonValue const_iterator::operator[](int 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 QJsonArray iterators behave like C++ pointers.
See also operator+().
© 2015 The Qt Company Ltd. Documentation contributions included herein are the copyrights of their respective owners. The documentation provided herein is licensed under the terms of the GNU Free Documentation License version 1.3 as published by the Free Software Foundation. Qt and respective logos are trademarks of The Qt Company Ltd in Finland and/or other countries worldwide. All other trademarks are property of their respective owners.