QJsonArray Class

The QJsonArray class encapsulates a JSON array. More...

Header: #include <QJsonArray>
qmake: QT += core
Since: Qt 5.0

This class was introduced in Qt 5.0.

Note: All functions in this class are reentrant.

Public Types

class const_iterator
class iterator
typedef ConstIterator
typedef Iterator
typedef const_pointer
typedef const_reference
typedef difference_type
typedef pointer
typedef reference
typedef size_type
typedef value_type

Public Functions

QJsonArray(const QJsonArray &other)
QJsonArray()
QJsonArray &operator=(const QJsonArray &other)
~QJsonArray()
void append(const QJsonValue &value)
QJsonValue at(int i) const
bool contains(const QJsonValue &value) const
QJsonValue first() const
void insert(int i, const QJsonValue &value)
bool isEmpty() const
QJsonValue last() const
void prepend(const QJsonValue &value)
void removeAt(int i)
void replace(int i, const QJsonValue &value)
int size() const
QJsonValue takeAt(int i)
QVariantList toVariantList() const
bool operator!=(const QJsonArray &other) const
bool operator==(const QJsonArray &other) const
QJsonValueRef operator[](int i)
QJsonValue operator[](int i) const

Static Public Members

QJsonArray fromStringList(const QStringList &list)
QJsonArray fromVariantList(const QVariantList &list)

Detailed Description

A JSON array is a list of values. The list can be manipulated by inserting and removing QJsonValue's from the array.

A QJsonArray can be converted to and from a QVariantList. You can query the number of entries with size(), insert(), and removeAt() entries from it and iterate over its content using the standard C++ iterator pattern.

QJsonArray 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.

See also JSON Support in Qt and JSON Save Game Example.

Member Type Documentation

typedef QJsonArray::ConstIterator

Qt-style synonym for QJsonArray::const_iterator.

typedef QJsonArray::Iterator

Qt-style synonym for QJsonArray::iterator.

typedef QJsonArray::const_pointer

Typedef for const QJsonValue *. Provided for STL compatibility.

typedef QJsonArray::const_reference

Typedef for const QJsonValue &. Provided for STL compatibility.

typedef QJsonArray::difference_type

Typedef for int. Provided for STL compatibility.

typedef QJsonArray::pointer

Typedef for QJsonValue *. Provided for STL compatibility.

typedef QJsonArray::reference

Typedef for QJsonValue &. Provided for STL compatibility.

typedef QJsonArray::size_type

Typedef for int. Provided for STL compatibility.

typedef QJsonArray::value_type

Typedef for QJsonValue. Provided for STL compatibility.

Member Function Documentation

QJsonArray::QJsonArray(const QJsonArray &other)

Creates a copy of other.

Since QJsonArray is implicitly shared, the copy is shallow as long as the object doesn't get modified.

QJsonArray::QJsonArray()

Creates an empty array.

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

Assigns other to this array.

QJsonArray::~QJsonArray()

Deletes the array.

void QJsonArray::append(const QJsonValue &value)

Inserts value at the end of the array.

See also prepend() and insert().

QJsonValue QJsonArray::at(int i) const

Returns a QJsonValue representing the value for index i.

The returned QJsonValue is Undefined, if i is out of bounds.

bool QJsonArray::contains(const QJsonValue &value) const

Returns true if the array contains an occurrence of value, otherwise false.

See also count().

QJsonValue QJsonArray::first() const

Returns the first value stored in the array.

Same as at(0).

See also at().

[static] QJsonArray QJsonArray::fromStringList(const QStringList &list)

Converts the string list list to a QJsonArray.

The values in list will be converted to JSON values.

See also toVariantList() and QJsonValue::fromVariant().

[static] QJsonArray QJsonArray::fromVariantList(const QVariantList &list)

Converts the variant list list to a QJsonArray.

The QVariant values in list will be converted to JSON values.

See also toVariantList() and QJsonValue::fromVariant().

void QJsonArray::insert(int i, const QJsonValue &value)

Inserts value at index position i in the array. If i is 0, the value is prepended to the array. If i is size(), the value is appended to the array.

See also append(), prepend(), replace(), and removeAt().

bool QJsonArray::isEmpty() const

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

See also size().

QJsonValue QJsonArray::last() const

Returns the last value stored in the array.

Same as at(size() - 1).

See also at().

void QJsonArray::prepend(const QJsonValue &value)

Inserts value at the beginning of the array.

This is the same as insert(0, value) and will prepend value to the array.

See also append() and insert().

void QJsonArray::removeAt(int i)

Removes the value at index position i. i must be a valid index position in the array (i.e., 0 <= i < size()).

See also insert() and replace().

void QJsonArray::replace(int i, const QJsonValue &value)

Replaces the item at index position i with value. i must be a valid index position in the array (i.e., 0 <= i < size()).

See also operator[]() and removeAt().

int QJsonArray::size() const

Returns the number of values stored in the array.

QJsonValue QJsonArray::takeAt(int i)

Removes the item at index position i and returns it. i must be a valid index position in the array (i.e., 0 <= i < size()).

If you don't use the return value, removeAt() is more efficient.

See also removeAt().

QVariantList QJsonArray::toVariantList() const

Converts this object to a QVariantList.

Returns the created map.

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

Returns true if this array is not equal to other.

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

Returns true if this array is equal to other.

QJsonValueRef QJsonArray::operator[](int i)

Returns the value at index position i as a modifiable reference. i must be a valid index position in the array (i.e., 0 <= i < size()).

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 at().

QJsonValue QJsonArray::operator[](int i) const

This is an overloaded function.

Same as at().