juce::var Class Reference

A variant class, that can be used to hold a range of primitive values. More...

#include <juce_Variant.h>

Collaboration diagram for juce::var:

Classes
struct	NativeFunctionArgs
	This structure is passed to a NativeFunction callback, and contains invocation details about the function's arguments and context. More...
union	ValueUnion

Public Types
using	NativeFunction = std::function< var(const NativeFunctionArgs &)>

Public Member Functions
	var () noexcept
	Creates a void variant. More...
	var (Array< var > &&)
	var (bool value) noexcept
	var (const Array< var > &value)
	var (const char *value)
	var (const MemoryBlock &binaryData)
	var (const String &value)
	var (const StringArray &value)
	var (const var &valueToCopy)
	var (const void *binaryData, size_t dataSize)
	var (const wchar_t *value)
	var (double value) noexcept
	var (int value) noexcept
	var (int64 value) noexcept
	var (MemoryBlock &&)
	var (NativeFunction method) noexcept
	var (ReferenceCountedObject *object)
	var (String &&)
	var (var &&) noexcept
	~var () noexcept
	Destructor. More...
void	append (const var &valueToAppend)
	Appends an element to the var, converting it to an array if it isn't already one. More...
var	call (const Identifier &method) const
	Invokes a named method call with no arguments. More...
var	call (const Identifier &method, const var &arg1) const
	Invokes a named method call with one argument. More...
var	call (const Identifier &method, const var &arg1, const var &arg2) const
	Invokes a named method call with 2 arguments. More...
var	call (const Identifier &method, const var &arg1, const var &arg2, const var &arg3)
	Invokes a named method call with 3 arguments. More...
var	call (const Identifier &method, const var &arg1, const var &arg2, const var &arg3, const var &arg4) const
	Invokes a named method call with 4 arguments. More...
var	call (const Identifier &method, const var &arg1, const var &arg2, const var &arg3, const var &arg4, const var &arg5) const
	Invokes a named method call with 5 arguments. More...
var	clone () const noexcept
	Returns a deep copy of this object. More...
bool	equals (const var &other) const noexcept
	Returns true if this var has the same value as the one supplied. More...
bool	equalsWithSameType (const var &other) const noexcept
	Returns true if this var has the same value and type as the one supplied. More...
Array< var > *	getArray () const noexcept
	If this variant holds an array, this provides access to it. More...
MemoryBlock *	getBinaryData () const noexcept
	If this variant holds a memory block, this provides access to it. More...
DynamicObject *	getDynamicObject () const noexcept
NativeFunction	getNativeFunction () const
	If this object is a method, this returns the function pointer. More...
ReferenceCountedObject *	getObject () const noexcept
var	getProperty (const Identifier &propertyName, const var &defaultReturnValue) const
	If this variant is an object, this returns one of its properties, or a default fallback value if the property is not set. More...
bool	hasProperty (const Identifier &propertyName) const noexcept
	Returns true if this variant is an object and if it has the given property. More...
bool	hasSameTypeAs (const var &other) const noexcept
	Returns true if this var has the same type as the one supplied. More...
int	indexOf (const var &value) const
	If the var is an array, this searches it for the first occurrence of the specified value, and returns its index. More...
void	insert (int index, const var &value)
	Inserts an element to the var, converting it to an array if it isn't already one. More...
var	invoke (const Identifier &method, const var *arguments, int numArguments) const
	Invokes a named method call with a list of arguments. More...
bool	isArray () const noexcept
bool	isBinaryData () const noexcept
bool	isBool () const noexcept
bool	isDouble () const noexcept
bool	isInt () const noexcept
bool	isInt64 () const noexcept
bool	isMethod () const noexcept
bool	isObject () const noexcept
bool	isString () const noexcept
bool	isUndefined () const noexcept
bool	isVoid () const noexcept
	operator bool () const noexcept
	operator double () const noexcept
	operator float () const noexcept
	operator int () const noexcept
	operator int64 () const noexcept
	operator String () const
var &	operator= (bool value)
var &	operator= (const Array< var > &value)
var &	operator= (const char *value)
var &	operator= (const MemoryBlock &value)
var &	operator= (const String &value)
var &	operator= (const var &valueToCopy)
var &	operator= (const wchar_t *value)
var &	operator= (double value)
var &	operator= (int value)
var &	operator= (int64 value)
var &	operator= (NativeFunction method)
var &	operator= (ReferenceCountedObject *object)
var &	operator= (String &&)
var &	operator= (var &&) noexcept
const var &	operator[] (const char *propertyName) const
	If this variant is an object, this returns one of its properties. More...
const var &	operator[] (const Identifier &propertyName) const
	If this variant is an object, this returns one of its properties. More...
var &	operator[] (int arrayIndex)
	If the var is an array, this can be used to return one of its elements. More...
const var &	operator[] (int arrayIndex) const
	If the var is an array, this can be used to return one of its elements. More...
void	remove (int index)
	If the var is an array, this removes one of its elements. More...
void	resize (int numArrayElementsWanted)
	Treating the var as an array, this resizes it to contain the specified number of elements. More...
int	size () const
	If the var is an array, this returns the number of elements. More...
void	swapWith (var &other) noexcept
String	toString () const
void	writeToStream (OutputStream &output) const
	Writes a binary representation of this value to a stream. More...

Static Public Member Functions
static var	readFromStream (InputStream &input)
	Reads back a stored binary representation of a value. More...
static var	undefined () noexcept
	Returns a var object that can be used where you need the javascript "undefined" value. More...

Private Member Functions
	var (const ReferenceCountedObject *)=delete
	var (const VariantType &) noexcept
	var (const void *)=delete
Array< var > *	convertToArray ()
var &	operator= (const ReferenceCountedObject *)=delete
var &	operator= (const void *)=delete

Private Attributes
const VariantType *	type
ValueUnion	value

Friends
bool	canCompare (const var &, const var &)

Detailed Description

A variant class, that can be used to hold a range of primitive values.

A var object can hold a range of simple primitive values, strings, or any kind of ReferenceCountedObject. The var class is intended to act like the kind of values used in dynamic scripting languages.

You can save/load var objects either in a small, proprietary binary format using writeToStream()/readFromStream(), or as JSON by using the JSON class.

See also

JSON, DynamicObject

@tags{Core}

Member Typedef Documentation

NativeFunction

using juce::var::NativeFunction = std::function<var (const NativeFunctionArgs&)>

Constructor & Destructor Documentation

var() [1/22]

juce::var::var ( )

noexcept

Creates a void variant.

~var()

juce::var::~var ( )

noexcept

Destructor.

var() [2/22]

juce::var::var

(

const var &

valueToCopy

)

var() [3/22]

juce::var::var ( int  value )

noexcept

var() [4/22]

juce::var::var ( int64  value )

noexcept

var() [5/22]

juce::var::var ( bool  value )

noexcept

var() [6/22]

juce::var::var ( double  value )

noexcept

var() [7/22]

juce::var::var

(

const char *

value

)

var() [8/22]

juce::var::var

(

const wchar_t *

value

)

var() [9/22]

juce::var::var

(

const String &

value

)

var() [10/22]

juce::var::var

(

const Array< var > &

value

)

var() [11/22]

juce::var::var

(

const StringArray &

value

)

var() [12/22]

juce::var::var

(

ReferenceCountedObject *

object

)

var() [13/22]

juce::var::var ( NativeFunction  method )

noexcept

var() [14/22]

juce::var::var	(	const void *	binaryData,
		size_t	dataSize
	)

var() [15/22]

juce::var::var

(

const MemoryBlock &

binaryData

)

var() [16/22]

juce::var::var ( var &&  )

noexcept

var() [17/22]

juce::var::var

(

String &&

)

var() [18/22]

juce::var::var

(

MemoryBlock &&

)

var() [19/22]

juce::var::var

(

Array< var > &&

)

var() [20/22]

juce::var::var ( const VariantType &  )

privatenoexcept

var() [21/22]

juce::var::var ( const ReferenceCountedObject *  )

privatedelete

var() [22/22]

juce::var::var ( const void *  )

privatedelete

Member Function Documentation

append()

void juce::var::append

(

const var &

valueToAppend

)

Appends an element to the var, converting it to an array if it isn't already one.

If the var isn't an array, it will be converted to one, and if its value was non-void, this value will be kept as the first element of the new array. The parameter value will then be appended to it. For more control over the array's contents, you can call getArray() and manipulate it directly as an Array<var>.

call() [1/6]

var juce::var::call

(

const Identifier &

method

)

const

Invokes a named method call with no arguments.

call() [2/6]

var juce::var::call	(	const Identifier &	method,
		const var &	arg1
	)		const

Invokes a named method call with one argument.

call() [3/6]

var juce::var::call	(	const Identifier &	method,
		const var &	arg1,
		const var &	arg2
	)		const

Invokes a named method call with 2 arguments.

call() [4/6]

var juce::var::call	(	const Identifier &	method,
		const var &	arg1,
		const var &	arg2,
		const var &	arg3
	)

Invokes a named method call with 3 arguments.

call() [5/6]

var juce::var::call	(	const Identifier &	method,
		const var &	arg1,
		const var &	arg2,
		const var &	arg3,
		const var &	arg4
	)		const

Invokes a named method call with 4 arguments.

call() [6/6]

var juce::var::call	(	const Identifier &	method,
		const var &	arg1,
		const var &	arg2,
		const var &	arg3,
		const var &	arg4,
		const var &	arg5
	)		const

Invokes a named method call with 5 arguments.

clone()

var juce::var::clone ( ) const

noexcept

Returns a deep copy of this object.

For simple types this just returns a copy, but if the object contains any arrays or DynamicObjects, they will be cloned (recursively).

convertToArray()

Array<var>* juce::var::convertToArray ( )

private

equals()

bool juce::var::equals ( const var &  other ) const

noexcept

Returns true if this var has the same value as the one supplied.

Note that this ignores the type, so a string var "123" and an integer var with the value 123 are considered to be equal.

Note that equality checking depends on the "wrapped" type of the object on which equals() is called. That means the following code will convert the right-hand-side argument to a string and compare the string values, because the object on the left-hand-side was initialised from a string:

var ("123").equals (var (123)) 

However, the following code will convert the right-hand-side argument to a double and compare the values as doubles, because the object on the left-hand-side was initialised from a double:

var (45.6).equals ("45.6000") 

See also

equalsWithSameType

equalsWithSameType()

bool juce::var::equalsWithSameType ( const var &  other ) const

noexcept

Returns true if this var has the same value and type as the one supplied.

This differs from equals() because e.g. "123" and 123 will be considered different.

See also

equals

Referenced by juce::ValueTreePropertyWithDefault::SynchronousValueSource::setValue().

getArray()

Array<var>* juce::var::getArray ( ) const

noexcept

If this variant holds an array, this provides access to it.

NOTE: Beware when you use this - the array pointer is only valid for the lifetime of the variant that returned it, so be very careful not to call this method on temporary var objects that are the return-value of a function, and which may go out of scope before you use the array!

Referenced by juce::ValueTreePropertyWithDefault::setValue(), and juce::varArrayToNSArray().

getBinaryData()

MemoryBlock* juce::var::getBinaryData ( ) const

noexcept

If this variant holds a memory block, this provides access to it.

NOTE: Beware when you use this - the MemoryBlock pointer is only valid for the lifetime of the variant that returned it, so be very careful not to call this method on temporary var objects that are the return-value of a function, and which may go out of scope before you use the MemoryBlock!

getDynamicObject()

DynamicObject* juce::var::getDynamicObject ( ) const

noexcept

Referenced by juce::varObjectToNSDictionary().

getNativeFunction()

NativeFunction juce::var::getNativeFunction

(

)

const

If this object is a method, this returns the function pointer.

getObject()

ReferenceCountedObject* juce::var::getObject ( ) const

noexcept

getProperty()

var juce::var::getProperty	(	const Identifier &	propertyName,
		const var &	defaultReturnValue
	)		const

If this variant is an object, this returns one of its properties, or a default fallback value if the property is not set.

hasProperty()

bool juce::var::hasProperty ( const Identifier &  propertyName ) const

noexcept

Returns true if this variant is an object and if it has the given property.

hasSameTypeAs()

bool juce::var::hasSameTypeAs ( const var &  other ) const

noexcept

Returns true if this var has the same type as the one supplied.

indexOf()

int juce::var::indexOf

(

const var &

value

)

const

If the var is an array, this searches it for the first occurrence of the specified value, and returns its index.

If the var isn't an array, or if the value isn't found, this returns -1.

insert()

void juce::var::insert	(	int	index,
		const var &	value
	)

Inserts an element to the var, converting it to an array if it isn't already one.

If the var isn't an array, it will be converted to one, and if its value was non-void, this value will be kept as the first element of the new array. The parameter value will then be inserted into it. For more control over the array's contents, you can call getArray() and manipulate it directly as an Array<var>.

invoke()

var juce::var::invoke	(	const Identifier &	method,
		const var *	arguments,
		int	numArguments
	)		const

Invokes a named method call with a list of arguments.

isArray()

bool juce::var::isArray ( ) const

noexcept

Referenced by juce::varArrayToNSArray(), and juce::varObjectToNSDictionary().

isBinaryData()

bool juce::var::isBinaryData ( ) const

noexcept

isBool()

bool juce::var::isBool ( ) const

noexcept

isDouble()

bool juce::var::isDouble ( ) const

noexcept

isInt()

bool juce::var::isInt ( ) const

noexcept

isInt64()

bool juce::var::isInt64 ( ) const

noexcept

isMethod()

bool juce::var::isMethod ( ) const

noexcept

isObject()

bool juce::var::isObject ( ) const

noexcept

Referenced by juce::varObjectToNSDictionary().

isString()

bool juce::var::isString ( ) const

noexcept

isUndefined()

bool juce::var::isUndefined ( ) const

noexcept

isVoid()

bool juce::var::isVoid ( ) const

noexcept

operator bool()

juce::var::operator bool ( ) const

noexcept

operator double()

juce::var::operator double ( ) const

noexcept

operator float()

juce::var::operator float ( ) const

noexcept

operator int()

juce::var::operator int ( ) const

noexcept

operator int64()

juce::var::operator int64 ( ) const

noexcept

operator String()

juce::var::operator String

(

)

const

operator=() [1/16]

var& juce::var::operator=

(

bool

value

)

operator=() [2/16]

var& juce::var::operator=

(

const Array< var > &

value

)

operator=() [3/16]

var& juce::var::operator=

(

const char *

value

)

operator=() [4/16]

var& juce::var::operator=

(

const MemoryBlock &

value

)

operator=() [5/16]

var& juce::var::operator= ( const ReferenceCountedObject *  )

privatedelete

operator=() [6/16]

var& juce::var::operator=

(

const String &

value

)

operator=() [7/16]

var& juce::var::operator=

(

const var &

valueToCopy

)

operator=() [8/16]

var& juce::var::operator= ( const void *  )

privatedelete

operator=() [9/16]

var& juce::var::operator=

(

const wchar_t *

value

)

operator=() [10/16]

var& juce::var::operator=

(

double

value

)

operator=() [11/16]

var& juce::var::operator=

(

int

value

)

operator=() [12/16]

var& juce::var::operator=

(

int64

value

)

operator=() [13/16]

var& juce::var::operator=

(

NativeFunction

method

)

operator=() [14/16]

var& juce::var::operator=

(

ReferenceCountedObject *

object

)

operator=() [15/16]

var& juce::var::operator=

(

String &&

)

operator=() [16/16]

var& juce::var::operator= ( var &&  )

noexcept

operator[]() [1/4]

const var& juce::var::operator[]

(

const char *

propertyName

)

const

If this variant is an object, this returns one of its properties.

operator[]() [2/4]

const var& juce::var::operator[]

(

const Identifier &

propertyName

)

const

If this variant is an object, this returns one of its properties.

operator[]() [3/4]

var& juce::var::operator[]

(

int

arrayIndex

)

If the var is an array, this can be used to return one of its elements.

To call this method, you must make sure that the var is actually an array, and that the index is a valid number. If these conditions aren't met, behaviour is undefined. For more control over the array's contents, you can call getArray() and manipulate it directly as an Array<var>.

operator[]() [4/4]

const var& juce::var::operator[]

(

int

arrayIndex

)

const

If the var is an array, this can be used to return one of its elements.

To call this method, you must make sure that the var is actually an array, and that the index is a valid number. If these conditions aren't met, behaviour is undefined. For more control over the array's contents, you can call getArray() and manipulate it directly as an Array<var>.

readFromStream()

static var juce::var::readFromStream ( InputStream &  input )

static

Reads back a stored binary representation of a value.

The data in the stream must have been written using writeToStream(), or this will have unpredictable results.

See also

JSON

remove()

void juce::var::remove

(

int

index

)

If the var is an array, this removes one of its elements.

If the index is out-of-range or the var isn't an array, nothing will be done. For more control over the array's contents, you can call getArray() and manipulate it directly as an Array<var>.

resize()

void juce::var::resize

(

int

numArrayElementsWanted

)

Treating the var as an array, this resizes it to contain the specified number of elements.

If the var isn't an array, it will be converted to one, and if its value was non-void, this value will be kept as the first element of the new array before resizing. For more control over the array's contents, you can call getArray() and manipulate it directly as an Array<var>.

size()

int juce::var::size

(

)

const

If the var is an array, this returns the number of elements.

If the var isn't actually an array, this will return 0.

swapWith()

void juce::var::swapWith ( var &  other )

noexcept

toString()

String juce::var::toString

(

)

const

Referenced by juce::varObjectToNSDictionary().

undefined()

static var juce::var::undefined ( )

staticnoexcept

Returns a var object that can be used where you need the javascript "undefined" value.

writeToStream()

void juce::var::writeToStream

(

OutputStream &

output

)

const

Writes a binary representation of this value to a stream.

The data can be read back later using readFromStream().

See also

JSON

Friends And Related Function Documentation

canCompare

bool canCompare ( const var &  , const var &    )

friend

Member Data Documentation

type

const VariantType* juce::var::type

private

value

ValueUnion juce::var::value

private

---

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

• juce_Variant.h