The QJsonObject class encapsulates a JSON object. More...

#include <qjsonobject.h>

Classes
class	const_iterator
	The QJsonObject::const_iterator class provides an STL-style const iterator for QJsonObject. More...

class	iterator
	The QJsonObject::iterator class provides an STL-style non-const iterator for QJsonObject. More...

Public Types
typedef iterator	Iterator

typedef const_iterator	ConstIterator

typedef QJsonValue	mapped_type

typedef QString	key_type

typedef qsizetype	size_type

Public Member Functions
	QJsonObject ()

	QJsonObject (std::initializer_list< QPair< QString, QJsonValue > > args)

	~QJsonObject ()

	QJsonObject (const QJsonObject &other)

QJsonObject &	operator= (const QJsonObject &other)

	QJsonObject (QJsonObject &&other) noexcept

QJsonObject &	operator= (QJsonObject &&other) noexcept

void	swap (QJsonObject &other) noexcept

QVariantMap	toVariantMap () const

QVariantHash	toVariantHash () const

QStringList	keys () const

qsizetype	size () const

qsizetype	count () const

qsizetype	length () const

bool	isEmpty () const

QJsonValue	value (const QString &key) const

QJsonValue	operator[] (const QString &key) const

QJsonValueRef	operator[] (const QString &key)

QJsonValue	value (QStringView key) const

QJsonValue	value (QLatin1String key) const

QJsonValue	operator[] (QStringView key) const

QJsonValue	operator[] (QLatin1String key) const

QJsonValueRef	operator[] (QStringView key)

QJsonValueRef	operator[] (QLatin1String key)

void	remove (const QString &key)

QJsonValue	take (const QString &key)

bool	contains (const QString &key) const

void	remove (QStringView key)

void	remove (QLatin1String key)

QJsonValue	take (QStringView key)

QJsonValue	take (QLatin1String key)

bool	contains (QStringView key) const

bool	contains (QLatin1String key) const

bool	operator== (const QJsonObject &other) const

bool	operator!= (const QJsonObject &other) const

iterator	begin ()

const_iterator	begin () const

const_iterator	constBegin () const

iterator	end ()

const_iterator	end () const

const_iterator	constEnd () const

iterator	erase (iterator it)

iterator	find (const QString &key)

const_iterator	find (const QString &key) const

const_iterator	constFind (const QString &key) const

iterator	insert (const QString &key, const QJsonValue &value)

iterator	find (QStringView key)

iterator	find (QLatin1String key)

const_iterator	find (QStringView key) const

const_iterator	find (QLatin1String key) const

const_iterator	constFind (QStringView key) const

const_iterator	constFind (QLatin1String key) const

iterator	insert (QStringView key, const QJsonValue &value)

iterator	insert (QLatin1String key, const QJsonValue &value)

bool	empty () const

Static Public Member Functions
static QJsonObject	fromVariantMap (const QVariantMap &map)

static QJsonObject	fromVariantHash (const QVariantHash &map)

Friends
class	iterator

class	const_iterator

class	QJsonValue

class	QJsonDocument

class	QJsonValueRef

class	QCborMap

Q_CORE_EXPORT QDebug	operator<< (QDebug, const QJsonObject &)

Detailed Description

The QJsonObject class encapsulates a JSON object.

\inmodule QtCore

\reentrant

Since: 5.0

A JSON object is a list of key value pairs, where the keys are unique strings and the values are represented by a QJsonValue.

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 object to and from text based JSON through QJsonDocument.

See also: {JSON Support in Qt}, {JSON Save Game Example}

Definition at line 55 of file qjsonobject.h.

Member Typedef Documentation

◆ ConstIterator

QJsonObject::ConstIterator

Qt-style synonym for QJsonObject::const_iterator.

Definition at line 260 of file qjsonobject.h.

◆ Iterator

QJsonObject::Iterator

Qt-style synonym for QJsonObject::iterator.

Definition at line 259 of file qjsonobject.h.

◆ key_type

QJsonObject::key_type

Typedef for QString. Provided for STL compatibility.

Definition at line 278 of file qjsonobject.h.

◆ mapped_type

QJsonObject::mapped_type

Typedef for QJsonValue. Provided for STL compatibility.

Definition at line 277 of file qjsonobject.h.

◆ size_type

QJsonObject::size_type

Typedef for qsizetype. Provided for STL compatibility.

Definition at line 279 of file qjsonobject.h.

Constructor & Destructor Documentation

◆ QJsonObject() [1/4]

QJsonObject::QJsonObject ( )

default

Constructs an empty JSON object.

See also: isEmpty()

◆ QJsonObject() [2/4]

QJsonObject::QJsonObject ( std::initializer_list< QPair< QString, QJsonValue > > args )

Since: 5.4 Constructs a QJsonObject instance initialized from args initialization list. For example:
QJsonObject object

{

{"property1", 1},

{"property2", 2}

};

QJsonObject
The QJsonObject class encapsulates a JSON object.
Definition: qjsonobject.h:56

Definition at line 148 of file qjsonobject.cpp.

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◆ ~QJsonObject()

QJsonObject::~QJsonObject ( )

default

Destroys the object.

◆ QJsonObject() [3/4]

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.

Definition at line 160 of file qjsonobject.cpp.

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◆ QJsonObject() [4/4]

QJsonObject::QJsonObject ( QJsonObject && other )

noexcept

Since: 5.10

Move-constructs a QJsonObject from other.

Definition at line 165 of file qjsonobject.cpp.

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Member Function Documentation

◆ begin() [1/2]

QJsonObject::iterator QJsonObject::begin ( )

inline

Returns an \l{STL-style iterators}{STL-style iterator} pointing to the first item in the object.

See also: constBegin(), end()

Definition at line 250 of file qjsonobject.h.

◆ begin() [2/2]

QJsonObject::const_iterator QJsonObject::begin ( ) const

inline

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Definition at line 251 of file qjsonobject.h.

◆ constBegin()

QJsonObject::const_iterator QJsonObject::constBegin ( ) const

inline

Returns a const \l{STL-style iterators}{STL-style iterator} pointing to the first item in the object.

See also: begin(), constEnd()

Definition at line 252 of file qjsonobject.h.

◆ constEnd()

QJsonObject::const_iterator QJsonObject::constEnd ( ) const

inline

Returns a const \l{STL-style iterators}{STL-style iterator} pointing to the imaginary item after the last item in the object.

See also: constBegin(), end()

Definition at line 255 of file qjsonobject.h.

◆ constFind() [1/3]

QJsonObject::const_iterator QJsonObject::constFind ( const QString & key ) const

Returns a 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().

Definition at line 792 of file qjsonobject.cpp.

◆ constFind() [2/3]

QJsonObject::const_iterator QJsonObject::constFind ( QLatin1String key ) const

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Since: 5.7

Definition at line 811 of file qjsonobject.cpp.

◆ constFind() [3/3]

QJsonObject::const_iterator QJsonObject::constFind ( QStringView key ) const

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Since: 5.14

Definition at line 802 of file qjsonobject.cpp.

◆ contains() [1/3]

bool QJsonObject::contains ( const QString & key ) const

Returns true if the object contains key key.

See also: insert(), remove(), take()

Definition at line 632 of file qjsonobject.cpp.

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◆ contains() [2/3]

bool QJsonObject::contains ( QLatin1String key ) const

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Since: 5.7

Definition at line 651 of file qjsonobject.cpp.

◆ contains() [3/3]

bool QJsonObject::contains ( QStringView key ) const

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Since: 5.14

Definition at line 642 of file qjsonobject.cpp.

◆ count()

qsizetype QJsonObject::count ( ) const

inline

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Same as size().

Definition at line 87 of file qjsonobject.h.

◆ empty()

bool QJsonObject::empty ( ) const

inline

This function is provided for STL compatibility. It is equivalent to isEmpty(), returning true if the object is empty; otherwise returning false.

Definition at line 281 of file qjsonobject.h.

◆ end() [1/2]

QJsonObject::iterator QJsonObject::end ( )

inline

Returns an \l{STL-style iterators}{STL-style iterator} pointing to the imaginary item after the last item in the object.

See also: begin(), constEnd()

Definition at line 253 of file qjsonobject.h.

◆ end() [2/2]

QJsonObject::const_iterator QJsonObject::end ( ) const

inline

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Definition at line 254 of file qjsonobject.h.

◆ erase()

QJsonObject::iterator QJsonObject::erase ( QJsonObject::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()

Definition at line 708 of file qjsonobject.cpp.

◆ find() [1/6]

QJsonObject::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().

Definition at line 727 of file qjsonobject.cpp.

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◆ find() [2/6]

QJsonObject::const_iterator QJsonObject::find ( const QString & key ) const

inline

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Definition at line 263 of file qjsonobject.h.

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◆ find() [3/6]

QJsonObject::iterator QJsonObject::find ( QLatin1String key )

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Since: 5.7

Definition at line 746 of file qjsonobject.cpp.

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◆ find() [4/6]

QJsonObject::const_iterator QJsonObject::find ( QLatin1String key ) const

inline

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Since: 5.7

Definition at line 270 of file qjsonobject.h.

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◆ find() [5/6]

QJsonObject::iterator QJsonObject::find ( QStringView key )

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Since: 5.14

Definition at line 737 of file qjsonobject.cpp.

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◆ find() [6/6]

QJsonObject::const_iterator QJsonObject::find ( QStringView key ) const

inline

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Since: 5.14

Definition at line 269 of file qjsonobject.h.

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◆ fromVariantHash()

QJsonObject QJsonObject::fromVariantHash ( const QVariantHash & hash )

static

Converts the variant hash hash to a QJsonObject.

Since: 5.5

The keys in hash will be used as the keys in the JSON object, and the QVariant values will be converted to JSON values.

Note: Conversion from \l QVariant is not completely lossless. Please see the documentation in QJsonValue::fromVariant() for more information.

See also: fromVariantMap(), toVariantHash(), QJsonValue::fromVariant()

Definition at line 242 of file qjsonobject.cpp.

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◆ fromVariantMap()

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.

Note: Conversion from \l QVariant is not completely lossless. Please see the documentation in QJsonValue::fromVariant() for more information.

See also: fromVariantHash(), toVariantMap(), QJsonValue::fromVariant()

Definition at line 213 of file qjsonobject.cpp.

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◆ insert() [1/3]

QJsonObject::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, end()

Definition at line 466 of file qjsonobject.cpp.

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◆ insert() [2/3]

QJsonObject::iterator QJsonObject::insert	(	QLatin1String	key,
		const QJsonValue &	value
	)

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Since: 5.14

Definition at line 485 of file qjsonobject.cpp.

◆ insert() [3/3]

QJsonObject::iterator QJsonObject::insert	(	QStringView	key,
		const QJsonValue &	value
	)

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Since: 5.14

Definition at line 476 of file qjsonobject.cpp.

◆ isEmpty()

bool QJsonObject::isEmpty ( ) const

Returns true if the object is empty. This is the same as size() == 0.

See also: size()

Definition at line 294 of file qjsonobject.cpp.

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◆ keys()

QStringList QJsonObject::keys ( ) const

Returns a list of all keys in this object.

The list is sorted lexographically.

Definition at line 270 of file qjsonobject.cpp.

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◆ length()

qsizetype QJsonObject::length ( ) const

inline

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Same as size().

Definition at line 88 of file qjsonobject.h.

◆ operator!=()

bool QJsonObject::operator!= ( const QJsonObject & other ) const

Returns true if other is not equal to this object.

Definition at line 696 of file qjsonobject.cpp.

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◆ operator=() [1/2]

QJsonObject & QJsonObject::operator= ( const QJsonObject & other )

Assigns other to this object.

Definition at line 174 of file qjsonobject.cpp.

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◆ operator=() [2/2]

QJsonObject & QJsonObject::operator= ( QJsonObject && other )

inlinenoexcept

Since: 5.10

Move-assigns other to this object.

Definition at line 69 of file qjsonobject.h.

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◆ operator==()

bool QJsonObject::operator== ( const QJsonObject & other ) const

Returns true if other is equal to this object.

Definition at line 673 of file qjsonobject.cpp.

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◆ operator[]() [1/6]

QJsonValueRef QJsonObject::operator[] ( const QString & key )

Returns a reference to the value for key. If there is no value with key key in the object, one is created with a QJsonValue::Null value and then returned.

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 element in the QJsonArray or QJsonObject from which you got the reference.

See also: value()

Definition at line 408 of file qjsonobject.cpp.

◆ operator[]() [2/6]

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 QJsonValue::Undefined if the key does not exist.

See also: value(), QJsonValue, QJsonValue::isUndefined()

Definition at line 374 of file qjsonobject.cpp.

◆ operator[]() [3/6]

QJsonValueRef QJsonObject::operator[] ( QLatin1String key )

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Since: 5.7

Definition at line 427 of file qjsonobject.cpp.

◆ operator[]() [4/6]

QJsonValue QJsonObject::operator[] ( QLatin1String key ) const

inline

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Since: 5.7

Definition at line 99 of file qjsonobject.h.

◆ operator[]() [5/6]

QJsonValueRef QJsonObject::operator[] ( QStringView key )

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Since: 5.14

Definition at line 418 of file qjsonobject.cpp.

◆ operator[]() [6/6]

QJsonValue QJsonObject::operator[] ( QStringView key ) const

inline

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Since: 5.14

Definition at line 98 of file qjsonobject.h.

◆ remove() [1/3]

void QJsonObject::remove ( const QString & key )

Removes key from the object.

See also: insert(), take()

Definition at line 531 of file qjsonobject.cpp.

◆ remove() [2/3]

void QJsonObject::remove ( QLatin1String key )

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Since: 5.14

Definition at line 550 of file qjsonobject.cpp.

◆ remove() [3/3]

void QJsonObject::remove ( QStringView key )

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Since: 5.14

Definition at line 541 of file qjsonobject.cpp.

◆ size()

qsizetype QJsonObject::size ( ) const

Returns the number of (key, value) pairs stored in the object.

Definition at line 284 of file qjsonobject.cpp.

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◆ swap()

void QJsonObject::swap ( QJsonObject & other )

inlinenoexcept

Since: 5.10

Swaps the object other with this. This operation is very fast and never fails.

Definition at line 75 of file qjsonobject.h.

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◆ take() [1/3]

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 returned QJsonValue is QJsonValue::Undefined.

See also: insert(), remove(), QJsonValue

Definition at line 582 of file qjsonobject.cpp.

◆ take() [2/3]

QJsonValue QJsonObject::take ( QLatin1String key )

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Since: 5.14

Definition at line 601 of file qjsonobject.cpp.

◆ take() [3/3]

QJsonValue QJsonObject::take ( QStringView key )

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Since: 5.14

Definition at line 592 of file qjsonobject.cpp.

◆ toVariantHash()

QVariantHash QJsonObject::toVariantHash ( ) const

Converts this object to a QVariantHash.

Since: 5.5

Returns the created hash.

See also: toVariantMap()

Definition at line 260 of file qjsonobject.cpp.

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◆ toVariantMap()

QVariantMap QJsonObject::toVariantMap ( ) const

Converts this object to a QVariantMap.

Returns the created map.

See also: toVariantHash()

Definition at line 225 of file qjsonobject.cpp.

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◆ value() [1/3]

QJsonValue QJsonObject::value ( const QString & key ) const

Returns a QJsonValue representing the value for the key key.

The returned QJsonValue is QJsonValue::Undefined if the key does not exist.

See also: QJsonValue, QJsonValue::isUndefined()

Definition at line 324 of file qjsonobject.cpp.

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◆ value() [2/3]

QJsonValue QJsonObject::value ( QLatin1String key ) const

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Since: 5.7

Definition at line 343 of file qjsonobject.cpp.

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◆ value() [3/3]

QJsonValue QJsonObject::value ( QStringView key ) const

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Since: 5.14

Definition at line 334 of file qjsonobject.cpp.

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Friends And Related Function Documentation

◆ const_iterator

friend class const_iterator

friend

Definition at line 247 of file qjsonobject.h.

◆ iterator

friend class iterator

friend

Definition at line 182 of file qjsonobject.h.

◆ operator<<

Q_CORE_EXPORT QDebug operator<<	(	QDebug	,
		const QJsonObject &
	)

friend

Definition at line 1474 of file qjsonobject.cpp.

◆ QCborMap

friend class QCborMap

friend

Definition at line 287 of file qjsonobject.h.

◆ QJsonDocument

friend class QJsonDocument

friend

Definition at line 285 of file qjsonobject.h.

◆ QJsonValue

friend class QJsonValue

friend

Definition at line 284 of file qjsonobject.h.

◆ QJsonValueRef

friend class QJsonValueRef

friend

Definition at line 286 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

Classes

Public Types

Public Member Functions

Static Public Member Functions

Friends

Detailed Description

Member Typedef Documentation

◆ ConstIterator

◆ Iterator

◆ key_type

◆ mapped_type

◆ size_type

Constructor & Destructor Documentation

◆ QJsonObject() [1/4]

◆ QJsonObject() [2/4]

◆ ~QJsonObject()

◆ QJsonObject() [3/4]

◆ QJsonObject() [4/4]

Member Function Documentation

◆ begin() [1/2]

◆ begin() [2/2]

◆ constBegin()

◆ constEnd()

◆ constFind() [1/3]

◆ constFind() [2/3]

◆ constFind() [3/3]

◆ contains() [1/3]

◆ contains() [2/3]

◆ contains() [3/3]

◆ count()

◆ empty()

◆ end() [1/2]

◆ end() [2/2]

◆ erase()

◆ find() [1/6]

◆ find() [2/6]

◆ find() [3/6]

◆ find() [4/6]

◆ find() [5/6]

◆ find() [6/6]

◆ fromVariantHash()

◆ fromVariantMap()

◆ insert() [1/3]

◆ insert() [2/3]

◆ insert() [3/3]

◆ isEmpty()

◆ keys()

◆ length()

◆ operator!=()

◆ operator=() [1/2]

◆ operator=() [2/2]

◆ operator==()

◆ operator[]() [1/6]

◆ operator[]() [2/6]

◆ operator[]() [3/6]

◆ operator[]() [4/6]

◆ operator[]() [5/6]

◆ operator[]() [6/6]

◆ remove() [1/3]

◆ remove() [2/3]

◆ remove() [3/3]

◆ size()

◆ swap()

◆ take() [1/3]

◆ take() [2/3]

◆ take() [3/3]

◆ toVariantHash()

◆ toVariantMap()

◆ value() [1/3]

◆ value() [2/3]

◆ value() [3/3]

Friends And Related Function Documentation

◆ const_iterator

◆ iterator

◆ operator<<

◆ QCborMap

◆ QJsonDocument

◆ QJsonValue

◆ QJsonValueRef