The QJsonObject::const_iterator class provides an STL-style const iterator for QJsonObject. More...
#include <qjsonobject.h>
Public Types | |
| typedef std::random_access_iterator_tag | iterator_category |
| typedef qsizetype | difference_type |
| typedef QJsonValue | value_type |
| typedef const QJsonValueRef | reference |
| typedef const QJsonValueRef * | pointer |
Friends | |
| class | iterator |
Detailed Description
The QJsonObject::const_iterator class provides an STL-style const iterator for QJsonObject.
\inmodule QtCore
- Since
- 5.0
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
- QJsonObject::iterator, {JSON Support in Qt}, {JSON Save Game Example}
Definition at line 184 of file qjsonobject.h.
Member Typedef Documentation
◆ difference_type
Definition at line 191 of file qjsonobject.h.
◆ iterator_category
A synonym for {std::random_access_iterator_tag} indicating this iterator is a random-access iterator.
- Note
- In Qt versions before 5.6, this was set by mistake to {std::bidirectional_iterator_tag}.
Definition at line 190 of file qjsonobject.h.
◆ pointer
Definition at line 194 of file qjsonobject.h.
◆ reference
Definition at line 193 of file qjsonobject.h.
◆ value_type
Definition at line 192 of file qjsonobject.h.
Constructor & Destructor Documentation
◆ const_iterator() [1/4]
|
inline |
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.
Definition at line 196 of file qjsonobject.h.
◆ const_iterator() [2/4]
|
inline |
Definition at line 197 of file qjsonobject.h.
◆ const_iterator() [3/4]
Constructs a copy of other.
Definition at line 199 of file qjsonobject.h.
◆ const_iterator() [4/4]
|
constexprdefault |
Member Function Documentation
◆ key()
|
inline |
◆ operator!=() [1/2]
|
inline |
◆ operator!=() [2/2]
|
inline |
Returns true if other points to a different item than this iterator; otherwise returns false.
- See also
- operator==()
Definition at line 239 of file qjsonobject.h.
◆ operator*()
|
inline |
Returns the current item's value.
Same as value().
- See also
- key()
Definition at line 212 of file qjsonobject.h.
◆ operator+()
|
inline |
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
- operator-()
Definition at line 230 of file qjsonobject.h.
◆ operator++() [1/2]
|
inline |
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
- operator--()
Definition at line 226 of file qjsonobject.h.
◆ operator++() [2/2]
|
inline |
This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.
The postfix ++ operator, {i++}, advances the iterator to the next item in the object and returns an iterator to the previously current item.
Definition at line 227 of file qjsonobject.h.
◆ operator+=()
|
inline |
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
- operator-=(), operator+()
Definition at line 233 of file qjsonobject.h.
◆ operator-() [1/2]
|
inline |
Returns the number of items between the item pointed to by other and the item pointed to by this iterator.
Definition at line 235 of file qjsonobject.h.
◆ operator-() [2/2]
|
inline |
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
- operator+()
Definition at line 232 of file qjsonobject.h.
◆ operator--() [1/2]
|
inline |
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
- operator++()
Definition at line 228 of file qjsonobject.h.
◆ operator--() [2/2]
|
inline |
This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.
The postfix – operator, {i–}, makes the preceding item current and returns an iterator pointing to the previously current item.
Definition at line 229 of file qjsonobject.h.
◆ operator-=()
|
inline |
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
- operator+=(), operator-()
Definition at line 234 of file qjsonobject.h.
◆ operator->()
|
inline |
Returns a pointer to the current item.
Definition at line 213 of file qjsonobject.h.
◆ operator<() [1/2]
|
inline |
Returns true if the item pointed to by this iterator is less than the item pointed to by the other iterator.
Definition at line 219 of file qjsonobject.h.
◆ operator<() [2/2]
◆ operator<=() [1/2]
|
inline |
Returns true if the item pointed to by this iterator is less than or equal to the item pointed to by the other iterator.
Definition at line 221 of file qjsonobject.h.
◆ operator<=() [2/2]
◆ operator=()
|
inline |
◆ operator==() [1/2]
|
inline |
◆ operator==() [2/2]
Returns true if other points to the same item as this iterator; otherwise returns false.
- See also
- operator!=()
Definition at line 237 of file qjsonobject.h.
◆ operator>() [1/2]
|
inline |
Returns true if the item pointed to by this iterator is greater than the item pointed to by the other iterator.
Definition at line 223 of file qjsonobject.h.
◆ operator>() [2/2]
◆ operator>=() [1/2]
|
inline |
Returns true if the item pointed to by this iterator is greater than or equal to the item pointed to by the other iterator.
Definition at line 224 of file qjsonobject.h.
◆ operator>=() [2/2]
◆ operator[]()
|
inline |
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
- operator+()
Definition at line 214 of file qjsonobject.h.
◆ value()
|
inline |
Returns the current item's value.
- See also
- key(), operator*()
Definition at line 211 of file qjsonobject.h.
Friends And Related Function Documentation
◆ iterator
|
friend |
Definition at line 186 of file qjsonobject.h.
The documentation for this class was generated from the following files:
- src/corelib/serialization/qjsonobject.h
- src/corelib/serialization/qjsonobject.cpp
