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Json::Value Class Reference

Represents a JSON value. More...

#include <json/value.h>

Public Types

typedef std::vector< std::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
 

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)
 
 Value (const char *beginValue, const char *endValue)
 
 Value (const StaticString &value)
 Constructs a value from a static string. More...
 
 Value (const std::string &value)
 
 Value (bool value)
 
 Value (const Value &other)
 
 ~Value ()
 
Valueoperator= (const Value &other)
 
void swap (Value &other)
 Swap values. More...
 
ValueType type () 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
 
bool operator== (const Value &other) const
 
bool operator!= (const Value &other) const
 
int compare (const Value &other) const
 
const char * asCString () const
 
std::string asString () const
 
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 isUInt () const
 
bool isIntegral () const
 
bool isDouble () const
 
bool isNumeric () const
 
bool isString () const
 
bool isArray () const
 
bool isObject () const
 
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...
 
bool operator! () const
 Return isNull() More...
 
void clear ()
 Remove all object members and array elements. More...
 
void resize (ArrayIndex size)
 Resize the array to size elements. More...
 
Valueoperator[] (ArrayIndex index)
 Access an array element (zero based index ). More...
 
Valueoperator[] (int index)
 Access an array element (zero based index ). More...
 
const Valueoperator[] (ArrayIndex index) const
 Access an array element (zero based index ) (You may need to say 'value[0u]' to get your compiler to distinguish this from the operator[] which takes a string.) More...
 
const Valueoperator[] (int index) const
 Access an array element (zero based index ) (You may need to say 'value[0u]' to get your compiler to distinguish this from the operator[] which takes a string.) More...
 
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...
 
Valueappend (const Value &value)
 Append value to array at the end. More...
 
Valueoperator[] (const char *key)
 Access an object value by name, create a null member if it does not exist. More...
 
const Valueoperator[] (const char *key) const
 Access an object value by name, returns null if there is no member with that name. More...
 
Valueoperator[] (const std::string &key)
 Access an object value by name, create a null member if it does not exist. More...
 
const Valueoperator[] (const std::string &key) const
 Access an object value by name, returns null if there is no member with that name. More...
 
Valueoperator[] (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 std::string &key, const Value &defaultValue) const
 Return the member named key if it exist, defaultValue otherwise. More...
 
Value removeMember (const char *key)
 Remove and return the named member. More...
 
Value removeMember (const std::string &key)
 Same as removeMember(const char*) More...
 
bool isMember (const char *key) const
 Return true if the object has a member named key. More...
 
bool isMember (const std::string &key) const
 Return true if the object has a member named key. More...
 
Members getMemberNames () const
 Return a list of the member names. More...
 
void setComment (const char *comment, CommentPlacement placement)
 Comments must be //... or /* ... */. More...
 
void setComment (const std::string &comment, CommentPlacement placement)
 Comments must be //... or /* ... */. More...
 
bool hasComment (CommentPlacement placement) const
 
std::string getComment (CommentPlacement placement) const
 Include delimiters and embedded newlines. More...
 
std::string toStyledString () const
 
const_iterator begin () const
 
const_iterator end () const
 
iterator begin ()
 
iterator end ()
 

Static Public Attributes

static const Value null
 
static const LargestInt minLargestInt = LargestInt( ~(LargestUInt(-1)/2) )
 Minimum signed integer value that can be stored in a Json::Value. More...
 
static const LargestInt maxLargestInt = LargestInt( LargestUInt(-1)/2 )
 Maximum signed integer value that can be stored in a Json::Value. More...
 
static const LargestUInt maxLargestUInt = LargestUInt(-1)
 Maximum unsigned integer value that can be stored in a Json::Value. More...
 
static const Int minInt = Int( ~(UInt(-1)/2) )
 Minimum signed int value that can be stored in a Json::Value. More...
 
static const Int maxInt = Int( UInt(-1)/2 )
 Maximum signed int value that can be stored in a Json::Value. More...
 
static const UInt maxUInt = UInt(-1)
 Maximum unsigned int value that can be stored in a Json::Value. More...
 
static const Int64 minInt64 = Int64( ~(UInt64(-1)/2) )
 Minimum signed 64 bits int value that can be stored in a Json::Value. More...
 
static const Int64 maxInt64 = Int64( UInt64(-1)/2 )
 Maximum signed 64 bits int value that can be stored in a Json::Value. More...
 
static const UInt64 maxUInt64 = UInt64(-1)
 Maximum unsigned 64 bits int value that can be stored in a Json::Value. More...
 

Friends

class ValueIteratorBase
 
class ValueInternalLink
 
class ValueInternalMap
 

Detailed Description

Represents a JSON value.

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

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 resize and initialized with nullValue. resize() can be used to enlarge or truncate an arrayValue.

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

It is possible to iterate over the list of a objectValue values using the getMemberNames() method.

Definition at line 118 of file value.h.

Member Typedef Documentation

Definition at line 137 of file value.h.

Definition at line 128 of file value.h.

Definition at line 130 of file value.h.

Definition at line 133 of file value.h.

Definition at line 127 of file value.h.

Definition at line 135 of file value.h.

Definition at line 136 of file value.h.

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

Definition at line 126 of file value.h.

Definition at line 129 of file value.h.

Definition at line 132 of file value.h.

Constructor & Destructor Documentation

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 236 of file json_value.cpp.

References Json::arrayAllocator(), Json::arrayValue, Json::booleanValue, Json::intValue, JSON_ASSERT_UNREACHABLE, Json::mapAllocator(), Json::ValueArrayAllocator::newArray(), Json::ValueMapAllocator::newMap(), Json::nullValue, Json::objectValue, Json::realValue, Json::stringValue, and Json::uintValue.

Referenced by operator[](), and resize().

Json::Value::Value ( Int  value)

Definition at line 291 of file json_value.cpp.

Json::Value::Value ( UInt  value)

Definition at line 281 of file json_value.cpp.

Json::Value::Value ( Int64  value)

Definition at line 304 of file json_value.cpp.

Json::Value::Value ( UInt64  value)

Definition at line 315 of file json_value.cpp.

Json::Value::Value ( double  value)

Definition at line 325 of file json_value.cpp.

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

Definition at line 335 of file json_value.cpp.

References Json::duplicateStringValue().

Json::Value::Value ( const char *  beginValue,
const char *  endValue 
)

Definition at line 347 of file json_value.cpp.

References Json::duplicateStringValue().

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. Example of usage:

Json::Value aValue( StaticString("some text") );

Definition at line 374 of file json_value.cpp.

References Json::StaticString::c_str().

Json::Value::Value ( const std::string &  value)

Definition at line 361 of file json_value.cpp.

References Json::duplicateStringValue().

Json::Value::Value ( bool  value)

Definition at line 399 of file json_value.cpp.

Json::Value::Value ( const Value other)
Json::Value::~Value ( )

Member Function Documentation

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

Append value to array at the end.

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

Definition at line 1230 of file json_value.cpp.

References size().

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

Definition at line 650 of file json_value.cpp.

References JSON_ASSERT, and Json::stringValue.

double Json::Value::asDouble ( ) const
float Json::Value::asFloat ( ) const
Value::Int Json::Value::asInt ( ) const
Value::Int64 Json::Value::asInt64 ( ) const
LargestInt Json::Value::asLargestInt ( ) const

Definition at line 809 of file json_value.cpp.

References asInt(), and asInt64().

LargestUInt Json::Value::asLargestUInt ( ) const

Definition at line 820 of file json_value.cpp.

References asUInt(), and asUInt64().

std::string Json::Value::asString ( ) const
Value::UInt Json::Value::asUInt ( ) const
Value::UInt64 Json::Value::asUInt64 ( ) const
Value::const_iterator Json::Value::begin ( ) const

Definition at line 1480 of file json_value.cpp.

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

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

Definition at line 1551 of file json_value.cpp.

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

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 1020 of file json_value.cpp.

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

Referenced by resize().

int Json::Value::compare ( const Value other) const
bool Json::Value::empty ( ) const

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

Definition at line 1003 of file json_value.cpp.

References isArray(), isNull(), isObject(), and size().

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

Definition at line 1515 of file json_value.cpp.

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

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

Definition at line 1586 of file json_value.cpp.

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

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 1158 of file json_value.cpp.

References null.

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

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

Definition at line 1237 of file json_value.cpp.

References null.

Value Json::Value::get ( const std::string &  key,
const Value defaultValue 
) const

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

Definition at line 1246 of file json_value.cpp.

std::string Json::Value::getComment ( CommentPlacement  placement) const

Include delimiters and embedded newlines.

Definition at line 1463 of file json_value.cpp.

References hasComment().

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 1317 of file json_value.cpp.

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

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

Definition at line 1457 of file json_value.cpp.

Referenced by getComment().

bool Json::Value::isArray ( ) const

Definition at line 1425 of file json_value.cpp.

References Json::arrayValue.

Referenced by empty(), Json::Path::make(), Json::Reader::parse(), and Json::Path::resolve().

bool Json::Value::isBool ( ) const

Definition at line 1374 of file json_value.cpp.

References Json::booleanValue.

bool Json::Value::isConvertibleTo ( ValueType  other) const
bool Json::Value::isDouble ( ) const

Definition at line 1404 of file json_value.cpp.

References Json::realValue.

Referenced by isNumeric().

bool Json::Value::isInt ( ) const

Definition at line 1381 of file json_value.cpp.

References Json::intValue.

bool Json::Value::isIntegral ( ) const

Definition at line 1395 of file json_value.cpp.

References Json::booleanValue, Json::intValue, and Json::uintValue.

Referenced by isNumeric().

bool Json::Value::isMember ( const char *  key) const

Return true if the object has a member named key.

Definition at line 1294 of file json_value.cpp.

References null.

Referenced by isMember().

bool Json::Value::isMember ( const std::string &  key) const

Return true if the object has a member named key.

Definition at line 1302 of file json_value.cpp.

References isMember().

bool Json::Value::isNull ( ) const

Definition at line 1367 of file json_value.cpp.

References Json::nullValue.

Referenced by empty(), and operator!().

bool Json::Value::isNumeric ( ) const

Definition at line 1411 of file json_value.cpp.

References isDouble(), and isIntegral().

bool Json::Value::isObject ( ) const

Definition at line 1432 of file json_value.cpp.

References Json::objectValue.

Referenced by empty(), Json::Path::make(), Json::Reader::parse(), and Json::Path::resolve().

bool Json::Value::isString ( ) const

Definition at line 1418 of file json_value.cpp.

References Json::stringValue.

bool Json::Value::isUInt ( ) const

Definition at line 1388 of file json_value.cpp.

References Json::uintValue.

bool Json::Value::isValidIndex ( ArrayIndex  index) const

Return true if index < size().

Definition at line 1167 of file json_value.cpp.

References size().

Referenced by Json::Path::resolve().

bool Json::Value::operator! ( ) const

Return isNull()

Definition at line 1013 of file json_value.cpp.

References isNull().

bool Json::Value::operator!= ( const Value other) const

Definition at line 644 of file json_value.cpp.

bool Json::Value::operator< ( const Value other) const
bool Json::Value::operator<= ( const Value other) const

Definition at line 582 of file json_value.cpp.

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

Definition at line 500 of file json_value.cpp.

References swap().

bool Json::Value::operator== ( const Value other) const
bool Json::Value::operator> ( const Value other) const

Definition at line 594 of file json_value.cpp.

bool Json::Value::operator>= ( const Value other) const

Definition at line 588 of file json_value.cpp.

Value & Json::Value::operator[] ( ArrayIndex  index)

Access an array element (zero based index ).

If the array contains less than index element, then null value are inserted in the array so that its size is index+1. (You may need to say 'value[0u]' to get your compiler to distinguish this from the operator[] which takes a string.)

Definition at line 1071 of file json_value.cpp.

References Json::arrayValue, JSON_ASSERT, null, Json::nullValue, and Value().

Value & Json::Value::operator[] ( int  index)

Access an array element (zero based index ).

If the array contains less than index element, then null value are inserted in the array so that its size is index+1. (You may need to say 'value[0u]' to get your compiler to distinguish this from the operator[] which takes a string.)

Definition at line 1092 of file json_value.cpp.

References JSON_ASSERT.

const Value & Json::Value::operator[] ( ArrayIndex  index) const

Access an array element (zero based index ) (You may need to say 'value[0u]' to get your compiler to distinguish this from the operator[] which takes a string.)

Definition at line 1100 of file json_value.cpp.

References Json::arrayValue, JSON_ASSERT, null, and Json::nullValue.

const Value & Json::Value::operator[] ( int  index) const

Access an array element (zero based index ) (You may need to say 'value[0u]' to get your compiler to distinguish this from the operator[] which takes a string.)

Definition at line 1119 of file json_value.cpp.

References JSON_ASSERT.

Value & Json::Value::operator[] ( const char *  key)

Access an object value by name, create a null member if it does not exist.

Definition at line 1127 of file json_value.cpp.

const Value & Json::Value::operator[] ( const char *  key) const

Access an object value by name, returns null if there is no member with that name.

Definition at line 1175 of file json_value.cpp.

References JSON_ASSERT, null, Json::nullValue, and Json::objectValue.

Value & Json::Value::operator[] ( const std::string &  key)

Access an object value by name, create a null member if it does not exist.

Definition at line 1194 of file json_value.cpp.

const Value & Json::Value::operator[] ( const std::string &  key) const

Access an object value by name, returns null if there is no member with that name.

Definition at line 1201 of file json_value.cpp.

Value & Json::Value::operator[] ( const StaticString key)

Access an object value by name, create a null member if it does not exist.

If the object as no entry for that name, then the member name used to store the new entry is not duplicated. Example of use:

Json::Value object;
static const StaticString code("code");
object[code] = 1234;

Definition at line 1207 of file json_value.cpp.

Value Json::Value::removeMember ( const char *  key)

Remove and return the named member.

Do nothing if it did not exist.

Returns
the removed Value, or null.
Precondition
type() is objectValue or nullValue
Postcondition
type() is unchanged

Definition at line 1253 of file json_value.cpp.

References JSON_ASSERT, null, Json::nullValue, and Json::objectValue.

Referenced by removeMember().

Value Json::Value::removeMember ( const std::string &  key)

Same as removeMember(const char*)

Definition at line 1279 of file json_value.cpp.

References removeMember().

void Json::Value::resize ( ArrayIndex  size)

Resize the array to size elements.

New elements are initialized to null. May only be called on nullValue or arrayValue.

Precondition
type() is arrayValue or nullValue
Postcondition
type() is arrayValue

Definition at line 1045 of file json_value.cpp.

References Json::arrayValue, clear(), JSON_ASSERT, Json::nullValue, size(), and Value().

void Json::Value::setComment ( const char *  comment,
CommentPlacement  placement 
)

Comments must be //... or /* ... */.

Definition at line 1439 of file json_value.cpp.

References Json::numberOfCommentPlacement.

Referenced by Json::Reader::parse(), and setComment().

void Json::Value::setComment ( const std::string &  comment,
CommentPlacement  placement 
)

Comments must be //... or /* ... */.

Definition at line 1449 of file json_value.cpp.

References setComment().

ArrayIndex Json::Value::size ( ) const
void Json::Value::swap ( Value other)

Swap values.

Note
Currently, comments are intentionally not swapped, for both logic and efficiency.

Definition at line 508 of file json_value.cpp.

Referenced by Json::ValueInternalMap::doActualRemove(), and operator=().

std::string Json::Value::toStyledString ( ) const

Definition at line 1472 of file json_value.cpp.

References Json::StyledWriter::write().

ValueType Json::Value::type ( ) const

Definition at line 520 of file json_value.cpp.

Friends And Related Function Documentation

friend class ValueInternalLink
friend

Definition at line 122 of file value.h.

friend class ValueInternalMap
friend

Definition at line 123 of file value.h.

friend class ValueIteratorBase
friend

Definition at line 120 of file value.h.

Member Data Documentation

const Int Json::Value::maxInt = Int( UInt(-1)/2 )
static

Maximum signed int value that can be stored in a Json::Value.

Definition at line 150 of file value.h.

Referenced by asInt(), and isConvertibleTo().

const Int64 Json::Value::maxInt64 = Int64( UInt64(-1)/2 )
static

Maximum signed 64 bits int value that can be stored in a Json::Value.

Definition at line 157 of file value.h.

Referenced by asInt64().

const LargestInt Json::Value::maxLargestInt = LargestInt( LargestUInt(-1)/2 )
static

Maximum signed integer value that can be stored in a Json::Value.

Definition at line 143 of file value.h.

const LargestUInt Json::Value::maxLargestUInt = LargestUInt(-1)
static

Maximum unsigned integer value that can be stored in a Json::Value.

Definition at line 145 of file value.h.

const UInt Json::Value::maxUInt = UInt(-1)
static

Maximum unsigned int value that can be stored in a Json::Value.

Definition at line 152 of file value.h.

Referenced by asUInt(), and isConvertibleTo().

const UInt64 Json::Value::maxUInt64 = UInt64(-1)
static

Maximum unsigned 64 bits int value that can be stored in a Json::Value.

Definition at line 159 of file value.h.

Referenced by asUInt64().

const Int Json::Value::minInt = Int( ~(UInt(-1)/2) )
static

Minimum signed int value that can be stored in a Json::Value.

Definition at line 148 of file value.h.

Referenced by asInt(), and isConvertibleTo().

const Int64 Json::Value::minInt64 = Int64( ~(UInt64(-1)/2) )
static

Minimum signed 64 bits int value that can be stored in a Json::Value.

Definition at line 155 of file value.h.

Referenced by asInt64().

const LargestInt Json::Value::minLargestInt = LargestInt( ~(LargestUInt(-1)/2) )
static

Minimum signed integer value that can be stored in a Json::Value.

Definition at line 141 of file value.h.

const Value Json::Value::null
static

Definition at line 139 of file value.h.

Referenced by get(), isMember(), operator[](), removeMember(), and Json::Path::resolve().


The documentation for this class was generated from the following files:

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