QJsonObject Class
The QJsonObject class encapsulates a JSON object. More...
#include <QJsonObject>
Note: All functions in this class are reentrant.
This class was introduced in QtCore 5.0.
- List of all members, including inherited members
Public Types
| class | const_iterator |
| class | iterator |
| typedef | ConstIterator |
| typedef | Iterator |
| typedef | key_type |
| typedef | mapped_type |
| typedef | size_type |
Public Functions
| QJsonObject() | |
| QJsonObject(const QJsonObject & other) | |
| ~QJsonObject() | |
| iterator | begin() |
| const_iterator | begin() const |
| const_iterator | constBegin() const |
| const_iterator | constEnd() const |
| const_iterator | constFind(const QString & key) const |
| bool | contains(const QString & key) const |
| int | count() const |
| bool | empty() const |
| iterator | end() |
| const_iterator | end() const |
| iterator | erase(iterator it) |
| iterator | find(const QString & key) |
| const_iterator | find(const QString & key) const |
| iterator | insert(const QString & key, const QJsonValue & value) |
| bool | isEmpty() const |
| QStringList | keys() const |
| int | length() const |
| void | remove(const QString & key) |
| int | size() const |
| QJsonValue | take(const QString & key) |
| QVariantMap | toVariantMap() const |
| QJsonValue | value(const QString & key) const |
| bool | operator!=(const QJsonObject & other) const |
| QJsonObject & | operator=(const QJsonObject & other) |
| bool | operator==(const QJsonObject & other) const |
| QJsonValue | operator[](const QString & key) const |
| QJsonValueRef | operator[](const QString & key) |
Static Public Members
| QJsonObject | fromVariantMap(const QVariantMap & map) |
Detailed Description
The QJsonObject class encapsulates a JSON object.
A JSON object is a list of key value pairs, where the keys are unique strings and the values are represented by aQJsonValue.
A QJsonObject can be converted to and from a QVariantMap. You can query the number of (key, value) pairs with size(),insert(), and remove() entries from it and iterate over its content using the standard C++ iterator pattern.
QJsonObject is an implicitly shared class, and shares the data with the document it has been created from as long as it is not being modified.
You can convert the array to and from text based JSON through QJsonDocument.
Member Type Documentation
typedef QJsonObject::ConstIterator
Qt-style synonym for QJsonObject::const_iterator.
typedef QJsonObject::Iterator
Qt-style synonym for QJsonObject::iterator.
typedef QJsonObject::key_type
Typedef for QString. Provided for STL compatibility.
typedef QJsonObject::mapped_type
Typedef for QJsonValue. Provided for STL compatibility.
typedef QJsonObject::size_type
Typedef for int. Provided for STL compatibility.
Member Function Documentation
QJsonObject::QJsonObject()
Constructs an empty JSON object
See also isEmpty().
QJsonObject::QJsonObject(const QJsonObject & other)
Creates a copy of other.
Since QJsonObject is implicitly shared, the copy is shallow as long as the object does not get modified.
QJsonObject::~QJsonObject()
Destroys the object.
iterator QJsonObject::begin()
Returns an STL-style iterator pointing to the first item in the object.
See also constBegin() and end().
const_iterator QJsonObject::begin() const
This is an overloaded function.
const_iterator QJsonObject::constBegin() const
Returns a const STL-style iterator pointing to the first item in the object.
See also begin() and constEnd().
const_iterator QJsonObject::constEnd() const
Returns a const STL-style iterator pointing to the imaginary item after the last item in the object.
See also constBegin() and end().
const_iterator QJsonObject::constFind(const QString & key) const
Returns an const iterator pointing to the item with key key in the map.
If the map contains no item with key key, the function returns constEnd().
bool QJsonObject::contains(const QString & key) const
Returns true if the object contains key key.
See also insert(), remove(), and take().
int QJsonObject::count() const
This is an overloaded function.
Same as size().
bool QJsonObject::empty() const
This function is provided for STL compatibility. It is equivalent to isEmpty(), returning true if the object is empty; otherwise returning false.
iterator QJsonObject::end()
Returns an STL-style iterator pointing to the imaginary item after the last item in the object.
See also begin() and constEnd().
const_iterator QJsonObject::end() const
This is an overloaded function.
iterator QJsonObject::erase(iterator it)
Removes the (key, value) pair pointed to by the iterator it from the map, and returns an iterator to the next item in the map.
See also remove().
iterator QJsonObject::find(const QString & key)
Returns an iterator pointing to the item with key key in the map.
If the map contains no item with key key, the function returns end().
const_iterator QJsonObject::find(const QString & key) const
This is an overloaded function.
QJsonObject QJsonObject::fromVariantMap(const QVariantMap & map) [static]
Converts the variant map map to a QJsonObject.
The keys in map will be used as the keys in the JSON object, and the QVariant values will be converted to JSON values.
See also toVariantMap() and QJsonValue::fromVariant().
iterator QJsonObject::insert(const QString & key, const QJsonValue & value)
Inserts a new item with the key key and a value of value.
If there is already an item with the key key then that item's value is replaced with value.
Returns an iterator pointing to the inserted item.
If the value is QJsonValue::Undefined, it will cause the key to get removed from the object. The returned iterator will then point to end()
See also remove(), take(), QJsonObject::iterator, and end().
bool QJsonObject::isEmpty() const
Returns true if the object is empty. This is the same as size() == 0.
See also size().
QStringList QJsonObject::keys() const
Returns a list of all keys in this object.
int QJsonObject::length() const
This is an overloaded function.
Same as size().
void QJsonObject::remove(const QString & key)
Removes key from the object.
See also insert() and take().
int QJsonObject::size() const
Returns the number of (key, value) pairs stored in the object.
QJsonValue QJsonObject::take(const QString & key)
Removes key from the object.
Returns a QJsonValue containing the value referenced by key. If key was not contained in the object, the returnedQJsonValue is Undefined.
See also insert(), remove(), and QJsonValue.
QVariantMap QJsonObject::toVariantMap() const
Converts this object to a QVariantMap.
Returns the created map.
QJsonValue QJsonObject::value(const QString & key) const
Returns a QJsonValue representing the value for the key key.
The returned QJsonValue is Undefined, if the key does not exist.
See also QJsonValue and QJsonValue::isUndefined().
bool QJsonObject::operator!=(const QJsonObject & other) const
Returns true if other is not equal to this object
QJsonObject & QJsonObject::operator=(const QJsonObject & other)
Assigns other to this object.
bool QJsonObject::operator==(const QJsonObject & other) const
Returns true if other is equal to this object
QJsonValue QJsonObject::operator[](const QString & key) const
Returns a QJsonValue representing the value for the key key.
This does the same as value().
The returned QJsonValue is Undefined, if the key does not exist.
See also value(), QJsonValue, and QJsonValue::isUndefined().
QJsonValueRef QJsonObject::operator[](const QString & key)
Returns a reference to the value for key.
The return value is of type QJsonValueRef, a helper class for QJsonArray and QJsonObject. When you get an object of type QJsonValueRef, you can use it as if it were a reference to a QJsonValue. If you assign to it, the assignment will apply to the character in the QJsonArray of QJsonObject from which you got the reference.
See also value().