Represents a JSON value. More...

#include <json/value.h>

Public Types
typedef std::vector< String >	Members

typedef ValueIterator	iterator

typedef ValueConstIterator	const_iterator

typedef Json::UInt	UInt

typedef Json::Int	Int

typedef Json::UInt64	UInt64

typedef Json::Int64	Int64

typedef Json::LargestInt	LargestInt

typedef Json::LargestUInt	LargestUInt

typedef Json::ArrayIndex	ArrayIndex

typedef std::string	value_type

Public Member Functions
	Value (ValueType type=nullValue)
	Create a default Value of the given type. More...

	Value (Int value)

	Value (UInt value)

	Value (Int64 value)

	Value (UInt64 value)

	Value (double value)

	Value (const char *value)
	Copy til first 0. (NULL causes to seg-fault.) More...

	Value (const char begin, const char end)
	Copy all, incl zeroes. More...

	Value (const StaticString &value)
	Constructs a value from a static string. More...

	Value (const String &value)

	Value (bool value)

	Value (const Value &other)

	Value (Value &&other)

	~Value ()

Value &	operator= (const Value &other)

Value &	operator= (Value &&other)

void	swap (Value &other)
	Swap everything. More...

void	swapPayload (Value &other)
	Swap values but leave comments and source offsets in place. More...

void	copy (const Value &other)
	copy everything. More...

void	copyPayload (const Value &other)
	copy values but leave comments and source offsets in place. More...

ValueType	type () const

bool	operator< (const Value &other) const
	Compare payload only, not comments etc. More...

bool	operator<= (const Value &other) const

bool	operator>= (const Value &other) const

bool	operator> (const Value &other) const

bool	operator== (const Value &other) const

bool	operator!= (const Value &other) const

int	compare (const Value &other) const

const char *	asCString () const
	Embedded zeroes could cause you trouble! More...

String	asString () const
	Embedded zeroes are possible. More...

bool	getString (char const begin, char const end) const
	Get raw char* of string-value. More...

Int	asInt () const

UInt	asUInt () const

Int64	asInt64 () const

UInt64	asUInt64 () const

LargestInt	asLargestInt () const

LargestUInt	asLargestUInt () const

float	asFloat () const

double	asDouble () const

bool	asBool () const

bool	isNull () const

bool	isBool () const

bool	isInt () const

bool	isInt64 () const

bool	isUInt () const

bool	isUInt64 () const

bool	isIntegral () const

bool	isDouble () const

bool	isNumeric () const

bool	isString () const

bool	isArray () const

bool	isObject () const

template<typename T >
T	as () const =delete
	The `as<T>` and `is<T>` member function templates and specializations. More...

template<typename T >
bool	is () const =delete

bool	isConvertibleTo (ValueType other) const

ArrayIndex	size () const
	Number of values in array or object. More...

bool	empty () const
	Return true if empty array, empty object, or null; otherwise, false. More...

	operator bool () const
	Return !isNull() More...

void	clear ()
	Remove all object members and array elements. More...

void	resize (ArrayIndex newSize)
	Resize the array to newSize elements. More...

Value &	operator[] (ArrayIndex index)
	Access an array element (zero based index). More...

Value &	operator[] (int index)

const Value &	operator[] (ArrayIndex index) const
	Access an array element (zero based index). More...

const Value &	operator[] (int index) const

Value	get (ArrayIndex index, const Value &defaultValue) const
	If the array contains at least index+1 elements, returns the element value, otherwise returns defaultValue. More...

bool	isValidIndex (ArrayIndex index) const
	Return true if index < size(). More...

Value &	append (const Value &value)
	Append value to array at the end. More...

Value &	append (Value &&value)

bool	insert (ArrayIndex index, Value newValue)
	Insert value in array at specific index. More...

Value &	operator[] (const char *key)
	Access an object value by name, create a null member if it does not exist. More...

const Value &	operator[] (const char *key) const
	Access an object value by name, returns null if there is no member with that name. More...

Value &	operator[] (const String &key)
	Access an object value by name, create a null member if it does not exist. More...

const Value &	operator[] (const String &key) const
	Access an object value by name, returns null if there is no member with that name. More...

Value &	operator[] (const StaticString &key)
	Access an object value by name, create a null member if it does not exist. More...

Value	get (const char *key, const Value &defaultValue) const
	Return the member named key if it exist, defaultValue otherwise. More...

Value	get (const char begin, const char end, const Value &defaultValue) const
	Return the member named key if it exist, defaultValue otherwise. More...

Value	get (const String &key, const Value &defaultValue) const
	Return the member named key if it exist, defaultValue otherwise. More...

Value const *	find (char const begin, char const end) const
	Most general and efficient version of isMember()const, get()const, and operator[]const. More...

Value *	demand (char const begin, char const end)
	Most general and efficient version of object-mutators. More...

void	removeMember (const char *key)
	Remove and return the named member. More...

void	removeMember (const String &key)
	Same as removeMember(const char*) More...

bool	removeMember (const char key, Value removed)
	Same as removeMember(const char* begin, const char* end, Value* removed), but 'key' is null-terminated. More...

bool	removeMember (String const &key, Value *removed)
	Remove the named map member. More...

bool	removeMember (const char begin, const char end, Value *removed)
	Same as removeMember(String const& key, Value* removed) More...

bool	removeIndex (ArrayIndex index, Value *removed)
	Remove the indexed array element. More...

bool	isMember (const char *key) const
	Return true if the object has a member named key. More...

bool	isMember (const String &key) const
	Return true if the object has a member named key. More...

bool	isMember (const char begin, const char end) const
	Same as isMember(String const& key)const. More...

Members	getMemberNames () const
	Return a list of the member names. More...

	__declspec (deprecated("Use setComment(String const&) instead.")) void setComment(const char *comment

void	setComment (const char *comment, size_t len, CommentPlacement placement)
	Comments must be //... or /* ... *‍/. More...

void	setComment (String comment, CommentPlacement placement)
	Comments must be //... or /* ... *‍/. More...

bool	hasComment (CommentPlacement placement) const

String	getComment (CommentPlacement placement) const
	Include delimiters and embedded newlines. More...

String	toStyledString () const

const_iterator	begin () const

const_iterator	end () const

iterator	begin ()

iterator	end ()

void	setOffsetStart (ptrdiff_t start)

void	setOffsetLimit (ptrdiff_t limit)

ptrdiff_t	getOffsetStart () const

ptrdiff_t	getOffsetLimit () const

template<>
bool	as () const

template<>
bool	is () const

template<>
Int	as () const

template<>
bool	is () const

template<>
UInt	as () const

template<>
bool	is () const

template<>
Int64	as () const

template<>
bool	is () const

template<>
UInt64	as () const

template<>
bool	is () const

template<>
double	as () const

template<>
bool	is () const

template<>
String	as () const

template<>
bool	is () const

template<>
float	as () const
	These `as` specializations are type conversions, and do not have a corresponding `is`. More...

template<>
const char *	as () const

Static Public Member Functions
static Value const &	nullSingleton ()

Public Attributes
CommentPlacement	placement

unsigned int	value_type_: 8

unsigned int	allocated_: 1

Static Public Attributes
static const Value &	null = Value::nullSingleton()

static const Value &	nullRef = Value::nullSingleton()

static constexpr LargestInt	minLargestInt
	Minimum signed integer value that can be stored in a Json::Value. More...

static constexpr LargestInt	maxLargestInt = LargestInt(LargestUInt(-1) / 2)
	Maximum signed integer value that can be stored in a Json::Value. More...

static constexpr LargestUInt	maxLargestUInt = LargestUInt(-1)
	Maximum unsigned integer value that can be stored in a Json::Value. More...

static constexpr Int	minInt = Int(~(UInt(-1) / 2))
	Minimum signed int value that can be stored in a Json::Value. More...

static constexpr Int	maxInt = Int(UInt(-1) / 2)
	Maximum signed int value that can be stored in a Json::Value. More...

static constexpr UInt	maxUInt = UInt(-1)
	Maximum unsigned int value that can be stored in a Json::Value. More...

static constexpr Int64	minInt64 = Int64(~(UInt64(-1) / 2))
	Minimum signed 64 bits int value that can be stored in a Json::Value. More...

static constexpr Int64	maxInt64 = Int64(UInt64(-1) / 2)
	Maximum signed 64 bits int value that can be stored in a Json::Value. More...

static constexpr UInt64	maxUInt64 = UInt64(-1)
	Maximum unsigned 64 bits int value that can be stored in a Json::Value. More...

static constexpr UInt	defaultRealPrecision = 17
	Default precision for real value for string representation. More...

static constexpr double	maxUInt64AsDouble = 18446744073709551615.0

Friends
class	ValueIteratorBase

Detailed Description

Represents a JSON value.

This class is a discriminated union wrapper that can represents a:

signed integer [range: Value::minInt - Value::maxInt]
unsigned integer (range: 0 - Value::maxUInt)
double
UTF-8 string
boolean
'null'
an ordered list of Value
collection of name/value pairs (javascript object)

The type of the held value is represented by a ValueType and can be obtained using type().

Values of an objectValue or arrayValue can be accessed using operator[]() methods. Non-const methods will automatically create the a nullValue element if it does not exist. The sequence of an arrayValue will be automatically resized and initialized with nullValue. resize() can be used to enlarge or truncate an arrayValue.

The get() methods can be used to obtain default value in the case the required element does not exist.

It is possible to iterate over the list of member keys of an object using the getMemberNames() method.

Note: Value string-length fit in size_t, but keys must be < 2^30. (The reason is an implementation detail.) A #CharReader will raise an exception if a bound is exceeded to avoid security holes in your app, but the Value API does not check bounds. That is the responsibility of the caller.

Definition at line 188 of file value.h.

Member Typedef Documentation

◆ ArrayIndex

typedef Json::ArrayIndex Json::Value::ArrayIndex

Definition at line 203 of file value.h.

◆ const_iterator

typedef ValueConstIterator Json::Value::const_iterator

Definition at line 194 of file value.h.

◆ Int

typedef Json::Int Json::Value::Int

Definition at line 196 of file value.h.

◆ Int64

typedef Json::Int64 Json::Value::Int64

Definition at line 199 of file value.h.

◆ iterator

typedef ValueIterator Json::Value::iterator

Definition at line 193 of file value.h.

◆ LargestInt

typedef Json::LargestInt Json::Value::LargestInt

Definition at line 201 of file value.h.

◆ LargestUInt

typedef Json::LargestUInt Json::Value::LargestUInt

Definition at line 202 of file value.h.

◆ Members

typedef std::vector<String> Json::Value::Members

Definition at line 192 of file value.h.

◆ UInt

typedef Json::UInt Json::Value::UInt

Definition at line 195 of file value.h.

◆ UInt64

typedef Json::UInt64 Json::Value::UInt64

Definition at line 198 of file value.h.

◆ value_type

typedef std::string Json::Value::value_type

Definition at line 206 of file value.h.

Constructor & Destructor Documentation

◆ Value() [1/13]

Json::Value::Value ( ValueType type = nullValue )

Create a default Value of the given type.

This is a very useful constructor. To create an empty array, pass arrayValue. To create an empty object, pass objectValue. Another Value can then be set to this one by assignment. This is useful since clear() and resize() will not alter types.

Examples:

Json::Value null_value; // null
Json::Value arr_value(Json::arrayValue); // []
Json::Value obj_value(Json::objectValue); // {}

Default constructor initialization must be equivalent to: memset( this, 0, sizeof(Value) ) This optimization is used in ValueInternalMap fast allocator.

Definition at line 343 of file json_value.cpp.

References Json::arrayValue, Json::booleanValue, Json::intValue, JSON_ASSERT_UNREACHABLE, Json::nullValue, Json::objectValue, Json::realValue, Json::stringValue, and Json::uintValue.

◆ Value() [2/13]

Json::Value::Value ( Int value )

Definition at line 372 of file json_value.cpp.

References Json::intValue.

◆ Value() [3/13]

Json::Value::Value ( UInt value )

Definition at line 377 of file json_value.cpp.

References Json::uintValue.

◆ Value() [4/13]

Json::Value::Value ( Int64 value )

Definition at line 382 of file json_value.cpp.

References Json::intValue.

◆ Value() [5/13]

Json::Value::Value ( UInt64 value )

Definition at line 386 of file json_value.cpp.

References Json::uintValue.

◆ Value() [6/13]

Json::Value::Value ( double value )

Definition at line 392 of file json_value.cpp.

References Json::realValue.

◆ Value() [7/13]

Json::Value::Value ( const char * value )

Copy til first 0. (NULL causes to seg-fault.)

Definition at line 397 of file json_value.cpp.

References Json::duplicateAndPrefixStringValue(), JSON_ASSERT_MESSAGE, and Json::stringValue.

◆ Value() [8/13]

Json::Value::Value	(	const char *	begin,
		const char *	end
	)

Copy all, incl zeroes.

Definition at line 405 of file json_value.cpp.

References Json::duplicateAndPrefixStringValue(), and Json::stringValue.

◆ Value() [9/13]

Json::Value::Value ( const StaticString & value )

Constructs a value from a static string.

Like other value string constructor but do not duplicate the string for internal storage. The given string must remain alive after the call to this constructor.

Note: This works only for null-terminated strings. (We cannot change the size of this class, so we have nowhere to store the length, which might be computed later for various operations.)

Example of usage:

static StaticString foo("some text");

Json::Value aValue(foo);

Definition at line 417 of file json_value.cpp.

References Json::StaticString::c_str(), and Json::stringValue.

◆ Value() [10/13]

Json::Value::Value ( const String & value )

Definition at line 411 of file json_value.cpp.

References Json::duplicateAndPrefixStringValue(), and Json::stringValue.

◆ Value() [11/13]

Json::Value::Value ( bool value )

Definition at line 430 of file json_value.cpp.

References Json::booleanValue.

◆ Value() [12/13]

Json::Value::Value ( const Value & other )

Definition at line 435 of file json_value.cpp.

◆ Value() [13/13]

Json::Value::Value ( Value && other )

Definition at line 440 of file json_value.cpp.

References Json::nullValue, and Json::swap().

◆ ~Value()

Json::Value::~Value ( )

Definition at line 445 of file json_value.cpp.

Member Function Documentation

◆ __declspec()

Json::Value::__declspec ( deprecated("Use setComment(String const&) instead.") ) const

Deprecated:: Always pass len.

◆ append() [1/2]

Value & Json::Value::append ( const Value & value )

Append value to array at the end.

Equivalent to jsonvalue[jsonvalue.size()] = value;

Definition at line 1150 of file json_value.cpp.

◆ append() [2/2]

Value & Json::Value::append ( Value && value )

Definition at line 1152 of file json_value.cpp.

References Json::arrayValue, JSON_ASSERT_MESSAGE, and Json::nullValue.

◆ as() [1/10]

template<>

bool Json::Value::as ( ) const

inline

Definition at line 680 of file value.h.

References asBool().

◆ as() [2/10]

template<>

Int Json::Value::as ( ) const

inline

Definition at line 683 of file value.h.

References asInt().

◆ as() [3/10]

template<>

UInt Json::Value::as ( ) const

inline

Definition at line 686 of file value.h.

References asUInt().

◆ as() [4/10]

template<>

Int64 Json::Value::as ( ) const

inline

Definition at line 690 of file value.h.

References asInt64().

◆ as() [5/10]

template<>

UInt64 Json::Value::as ( ) const

inline

Definition at line 693 of file value.h.

References asUInt64().

◆ as() [6/10]

template<>

double Json::Value::as ( ) const

inline

Definition at line 697 of file value.h.

References asDouble().

◆ as() [7/10]

template<>

String Json::Value::as ( ) const

inline

Definition at line 700 of file value.h.

References asString().

◆ as() [8/10]

template<>

float Json::Value::as ( ) const

inline

These as specializations are type conversions, and do not have a corresponding is.

Definition at line 705 of file value.h.

References asFloat().

◆ as() [9/10]

template<>

const char* Json::Value::as ( ) const

inline

Definition at line 706 of file value.h.

References asCString().

◆ as() [10/10]

template<typename T >

T Json::Value::as ( ) const

delete

The as<T> and is<T> member function templates and specializations.

◆ asBool()

bool Json::Value::asBool ( ) const

Definition at line 816 of file json_value.cpp.

References Json::booleanValue, Json::intValue, JSON_FAIL_MESSAGE, Json::nullValue, Json::realValue, and Json::uintValue.

Referenced by as(), Json::CharReaderBuilder::newCharReader(), and Json::StreamWriterBuilder::newStreamWriter().

◆ asCString()

const char * Json::Value::asCString ( ) const

Embedded zeroes could cause you trouble!

Definition at line 593 of file json_value.cpp.

References Json::decodePrefixedString(), JSON_ASSERT_MESSAGE, and Json::stringValue.

Referenced by as().

◆ asDouble()

double Json::Value::asDouble ( ) const

Definition at line 771 of file json_value.cpp.

References Json::booleanValue, Json::intValue, JSON_FAIL_MESSAGE, Json::nullValue, Json::realValue, and Json::uintValue.

Referenced by as().

◆ asFloat()

float Json::Value::asFloat ( ) const

Definition at line 793 of file json_value.cpp.

References Json::booleanValue, Json::intValue, JSON_FAIL_MESSAGE, Json::nullValue, Json::realValue, and Json::uintValue.

Referenced by as().

◆ asInt()

Value::Int Json::Value::asInt ( ) const

Definition at line 666 of file json_value.cpp.

References Json::booleanValue, Json::InRange(), Json::intValue, JSON_ASSERT_MESSAGE, JSON_FAIL_MESSAGE, Json::nullValue, Json::realValue, and Json::uintValue.

Referenced by as().

◆ asInt64()

Value::Int64 Json::Value::asInt64 ( ) const

Definition at line 712 of file json_value.cpp.

References Json::booleanValue, Json::InRange(), Json::intValue, JSON_ASSERT_MESSAGE, JSON_FAIL_MESSAGE, Json::nullValue, Json::realValue, and Json::uintValue.

Referenced by as().

◆ asLargestInt()

LargestInt Json::Value::asLargestInt ( ) const

Definition at line 755 of file json_value.cpp.

◆ asLargestUInt()

LargestUInt Json::Value::asLargestUInt ( ) const

Definition at line 763 of file json_value.cpp.

◆ asString()

String Json::Value::asString ( ) const

Embedded zeroes are possible.

Definition at line 631 of file json_value.cpp.

References Json::booleanValue, Json::decodePrefixedString(), Json::intValue, JSON_FAIL_MESSAGE, Json::nullValue, Json::realValue, Json::stringValue, Json::uintValue, and Json::valueToString().

Referenced by as(), and Json::StreamWriterBuilder::newStreamWriter().

◆ asUInt()

Value::UInt Json::Value::asUInt ( ) const

Definition at line 688 of file json_value.cpp.

References Json::booleanValue, Json::InRange(), Json::intValue, JSON_ASSERT_MESSAGE, JSON_FAIL_MESSAGE, Json::nullValue, Json::realValue, and Json::uintValue.

Referenced by as(), and Json::StreamWriterBuilder::newStreamWriter().

◆ asUInt64()

Value::UInt64 Json::Value::asUInt64 ( ) const

Definition at line 733 of file json_value.cpp.

References Json::booleanValue, Json::InRange(), Json::intValue, JSON_ASSERT_MESSAGE, JSON_FAIL_MESSAGE, Json::nullValue, Json::realValue, and Json::uintValue.

Referenced by as().

◆ begin() [1/2]

Value::iterator Json::Value::begin ( )

Definition at line 1532 of file json_value.cpp.

References Json::arrayValue, Json::objectValue, and type().

◆ begin() [2/2]

Value::const_iterator Json::Value::begin ( ) const

Definition at line 1506 of file json_value.cpp.

References Json::arrayValue, Json::objectValue, and type().

◆ clear()

void Json::Value::clear ( )

Remove all object members and array elements.

Precondition: type() is arrayValue, objectValue, or nullValue

Postcondition: type() is unchanged

Definition at line 903 of file json_value.cpp.

References Json::arrayValue, JSON_ASSERT_MESSAGE, Json::nullValue, and Json::objectValue.

◆ compare()

int Json::Value::compare ( const Value & other ) const

Definition at line 486 of file json_value.cpp.

◆ copy()

void Json::Value::copy ( const Value & other )

copy everything.

Definition at line 477 of file json_value.cpp.

◆ copyPayload()

void Json::Value::copyPayload ( const Value & other )

copy values but leave comments and source offsets in place.

Definition at line 465 of file json_value.cpp.

◆ demand()

Value * Json::Value::demand	(	char const *	begin,
		char const *	end
	)

Most general and efficient version of object-mutators.

Note: As stated elsewhere, behavior is undefined if (end-begin) >= 2^30

Returns: non-zero, but JSON_ASSERT if this is neither object nor nullValue.

Definition at line 1107 of file json_value.cpp.

References JSON_ASSERT_MESSAGE, Json::nullValue, and Json::objectValue.

◆ empty()

bool Json::Value::empty ( ) const

Return true if empty array, empty object, or null; otherwise, false.

Definition at line 894 of file json_value.cpp.

Referenced by Json::StreamWriterBuilder::validate(), and Json::CharReaderBuilder::validate().

◆ end() [1/2]

Value::iterator Json::Value::end ( )

Definition at line 1545 of file json_value.cpp.

References Json::arrayValue, Json::objectValue, and type().

◆ end() [2/2]

Value::const_iterator Json::Value::end ( ) const

Definition at line 1519 of file json_value.cpp.

References Json::arrayValue, Json::objectValue, and type().

◆ find()

Value const * Json::Value::find	(	char const *	begin,
		char const *	end
	)		const

Most general and efficient version of isMember()const, get()const, and operator[]const.

Note: As stated elsewhere, behavior is undefined if (end-begin) >= 2^30

Definition at line 1094 of file json_value.cpp.

References JSON_ASSERT_MESSAGE, Json::nullValue, and Json::objectValue.

◆ get() [1/4]

Value Json::Value::get	(	ArrayIndex	index,
		const Value &	defaultValue
	)		const

If the array contains at least index+1 elements, returns the element value, otherwise returns defaultValue.

Definition at line 1087 of file json_value.cpp.

◆ get() [2/4]

Value Json::Value::get	(	const char *	begin,
		const char *	end,
		const Value &	defaultValue
	)		const

Return the member named key if it exist, defaultValue otherwise.

Note: deep copy; key may contain embedded nulls.

Definition at line 1176 of file json_value.cpp.

◆ get() [3/4]

Value Json::Value::get	(	const char *	key,
		const Value &	defaultValue
	)		const

Return the member named key if it exist, defaultValue otherwise.

Note: deep copy

Definition at line 1181 of file json_value.cpp.

◆ get() [4/4]

Value Json::Value::get	(	const String &	key,
		const Value &	defaultValue
	)		const

Return the member named key if it exist, defaultValue otherwise.

Note: deep copy

Parameters

key	may contain embedded nulls.

Definition at line 1184 of file json_value.cpp.

◆ getComment()

String Json::Value::getComment ( CommentPlacement placement ) const

Include delimiters and embedded newlines.

Definition at line 1484 of file json_value.cpp.

References placement.

◆ getMemberNames()

Value::Members Json::Value::getMemberNames ( ) const

Return a list of the member names.

If null, return an empty list.

Precondition: type() is objectValue or nullValue

Postcondition: if type() was nullValue, it remains nullValue

Definition at line 1267 of file json_value.cpp.

References JSON_ASSERT_MESSAGE, Json::nullValue, and Json::objectValue.

Referenced by Json::StreamWriterBuilder::validate(), and Json::CharReaderBuilder::validate().

◆ getOffsetLimit()

ptrdiff_t Json::Value::getOffsetLimit ( ) const

Definition at line 1494 of file json_value.cpp.

◆ getOffsetStart()

ptrdiff_t Json::Value::getOffsetStart ( ) const

Definition at line 1492 of file json_value.cpp.

◆ getString()

bool Json::Value::getString	(	char const **	begin,
		char const **	end
	)		const

Get raw char* of string-value.

Returns: false if !string. (Seg-fault if str or end are NULL.)

Definition at line 619 of file json_value.cpp.

References Json::decodePrefixedString(), and Json::stringValue.

◆ hasComment()

bool Json::Value::hasComment ( CommentPlacement placement ) const

Definition at line 1480 of file json_value.cpp.

References placement.

Referenced by toStyledString().

◆ insert()

bool Json::Value::insert	(	ArrayIndex	index,
		Value	newValue
	)

Insert value in array at specific index.

Definition at line 1161 of file json_value.cpp.

References Json::arrayValue, JSON_ASSERT_MESSAGE, and Json::nullValue.