Json::Value Class Reference

Represents a JSON value. More...

`#include <json.h>`

Collaboration diagram for Json::Value:
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## 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
typedef std::map< CZString, Value > | ObjectValues
typedef CppTL::SmallMap< CZString, Value > | ObjectValues

## 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 (const CppTL::ConstString &value)
| Value (bool value)
| Value (const Value &other)
Value & | operator= (const Value &other)
void | swap (Value &other)
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
CppTL::ConstString | asConstString () 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.
bool | empty () const
| Return true if empty array, empty object, or null; otherwise, false.
bool | operator! () const
| Return isNull()
void | clear ()
void | resize (ArrayIndex size)
Value & | operator[] (ArrayIndex index)
Value & | operator[] (int index)
const Value & | operator[] (ArrayIndex index) const
const Value & | operator[] (int index) const
Value | get (ArrayIndex index, const Value &defaultValue) const
bool | isValidIndex (ArrayIndex index) const
| Return true if index < size().
Value & | append (const Value &value)
| Append value to array at the end. More...
Value & | operator[] (const char *key)
| Access an object value by name, create a null member if it does not exist.
const Value & | operator[] (const char *key) const
| Access an object value by name, returns null if there is no member with that name.
Value & | operator[] (const std::string &key)
| Access an object value by name, create a null member if it does not exist.
const Value & | operator[] (const std::string &key) const
| Access an object value by name, returns null if there is no member with that name.
Value & | operator[] (const StaticString &key)
| Access an object value by name, create a null member if it does not exist. More...
Value & | operator[] (const CppTL::ConstString &key)
| Access an object value by name, create a null member if it does not exist.
const Value & | operator[] (const CppTL::ConstString &key) const
| Access an object value by name, returns null if there is no member with that name.
Value | get (const char *key, const Value &defaultValue) const
| Return the member named key if it exist, defaultValue otherwise.
Value | get (const std::string &key, const Value &defaultValue) const
| Return the member named key if it exist, defaultValue otherwise.
Value | get (const CppTL::ConstString &key, const Value &defaultValue) const
| Return the member named key if it exist, defaultValue otherwise.
Value | removeMember (const char *key)
| Remove and return the named member. More...
Value | removeMember (const std::string &key)
| Same as removeMember(const char*)
bool | isMember (const char *key) const
| Return true if the object has a member named key.
bool | isMember (const std::string &key) const
| Return true if the object has a member named key.
bool | isMember (const CppTL::ConstString &key) const
| Return true if the object has a member named key.
Members | getMemberNames () const
| Return a list of the member names. More...
void | setComment (const char *comment, CommentPlacement placement)
| Comments must be //... or /* ... */.
void | setComment (const std::string &comment, CommentPlacement placement)
| Comments must be //... or /* ... */.
bool | hasComment (CommentPlacement placement) const
std::string | getComment (CommentPlacement placement) const
| Include delimiters and embedded newlines.
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.
static const LargestInt | maxLargestInt = LargestInt(LargestUInt(-1) / 2)
| Maximum signed integer value that can be stored in a Json::Value.
static const LargestUInt | maxLargestUInt = LargestUInt(-1)
| Maximum unsigned integer value that can be stored in a Json::Value.
static const Int | minInt = Int(~(UInt(-1) / 2))
| Minimum signed int value that can be stored in a Json::Value.
static const Int | maxInt = Int(UInt(-1) / 2)
| Maximum signed int value that can be stored in a Json::Value.
static const UInt | maxUInt = UInt(-1)
| Maximum unsigned int value that can be stored in a Json::Value.
static const Int64 | minInt64 = Int64(~(UInt64(-1) / 2))
| Minimum signed 64 bits int value that can be stored in a Json::Value.
static const Int64 | maxInt64 = Int64(UInt64(-1) / 2)
| Maximum signed 64 bits int value that can be stored in a Json::Value.
static const UInt64 | maxUInt64 = UInt64(-1)
| Maximum unsigned 64 bits int value that can be stored in a Json::Value.

## Friends

class | ValueIteratorBase
class | ValueInternalLink
class | ValueInternalMap

## 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 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.

## 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); // {}

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") );

## Member Function Documentation

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

Append value to array at the end.

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

void Json::Value::clear | ( |  | ) |

Remove all object members and array elements.

Precondition
  type() is arrayValue, objectValue, or nullValue

Postcondition
  type() is unchanged

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.

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

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.)

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.)

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.)

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.)

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;

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

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

void Json::Value::swap | ( | Value & | other | ) |

Swap values.

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

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

- json.h
- jsoncpp.cpp