var Class Reference

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

#include <juce_Variant.h>

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

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

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

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

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

Member Typedef Documentation

NativeFunction

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

Constructor & Destructor Documentation

var() [1/19]

var::var ( )

noexcept

Creates a void variant.

~var()

var::~var ( )

noexcept

Destructor.

var() [2/19]

var::var

(

const var &

valueToCopy

)

var() [3/19]

var::var ( int value )

noexcept

var() [4/19]

var::var ( int64 value )

noexcept

var() [5/19]

var::var ( bool value )

noexcept

var() [6/19]

var::var ( double value )

noexcept

var() [7/19]

var::var

(

const char *

value

)

var() [8/19]

var::var

(

const wchar_t *

value

)

var() [9/19]

var::var

(

const String &

value

)

var() [10/19]

var::var

(

const Array< var > &

value

)

var() [11/19]

var::var

(

const StringArray &

value

)

var() [12/19]

var::var

(

ReferenceCountedObject *

object

)

var() [13/19]

var::var ( NativeFunction method )

noexcept

var() [14/19]

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

var() [15/19]

var::var

(

const MemoryBlock &

binaryData

)

var() [16/19]

var::var ( var && )

noexcept

var() [17/19]

var::var

(

String &&

)

var() [18/19]

var::var

(

MemoryBlock &&

)

var() [19/19]

var::var

(

Array< var > &&

)

Member Function Documentation

operator=() [1/14]

var & var::operator=

(

const var &

valueToCopy

)

operator=() [2/14]

var & var::operator=

(

int

value

)

operator=() [3/14]

var & var::operator=

(

int64

value

)

operator=() [4/14]

var & var::operator=

(

bool

value

)

operator=() [5/14]

var & var::operator=

(

double

value

)

operator=() [6/14]

var & var::operator=

(

const char *

value

)

operator=() [7/14]

var & var::operator=

(

const wchar_t *

value

)

operator=() [8/14]

var & var::operator=

(

const String &

value

)

operator=() [9/14]

var & var::operator=

(

const MemoryBlock &

value

)

operator=() [10/14]

var & var::operator=

(

const Array< var > &

value

)

operator=() [11/14]

var & var::operator=

(

ReferenceCountedObject *

object

)

operator=() [12/14]

var & var::operator=

(

NativeFunction

method

)

operator=() [13/14]

var & var::operator= ( var && )

noexcept

operator=() [14/14]

var & var::operator=

(

String &&

)

swapWith()

void var::swapWith ( var & other )

noexcept

undefined()

static var var::undefined ( )

staticnoexcept

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

operator int()

var::operator int ( ) const

noexcept

operator int64()

var::operator int64 ( ) const

noexcept

operator bool()

var::operator bool ( ) const

noexcept

operator float()

var::operator float ( ) const

noexcept

operator double()

var::operator double ( ) const

noexcept

operator String()

var::operator String

(

)

const

toString()

String var::toString

(

)

const

getArray()

Array< var > * 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 ValueTreePropertyWithDefault::setValue().

getBinaryData()

MemoryBlock * 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!

getObject()

ReferenceCountedObject * var::getObject ( ) const

noexcept

getDynamicObject()

DynamicObject * var::getDynamicObject ( ) const

noexcept

isVoid()

bool var::isVoid ( ) const

noexcept

isUndefined()

bool var::isUndefined ( ) const

noexcept

isInt()

bool var::isInt ( ) const

noexcept

isInt64()

bool var::isInt64 ( ) const

noexcept

isBool()

bool var::isBool ( ) const

noexcept

isDouble()

bool var::isDouble ( ) const

noexcept

isString()

bool var::isString ( ) const

noexcept

isObject()

bool var::isObject ( ) const

noexcept

isArray()

bool var::isArray ( ) const

noexcept

isBinaryData()

bool var::isBinaryData ( ) const

noexcept

isMethod()

bool var::isMethod ( ) const

noexcept

equals()

bool 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 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

hasSameTypeAs()

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

noexcept

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

clone()

var 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).

size()

int 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.

operator[]() [1/4]

const var & 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>.

operator[]() [2/4]

var & 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>.

append()

void 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>.

insert()

void 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>.

remove()

void 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 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>.

indexOf()

int 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.

operator[]() [3/4]

const var & var::operator[]

(

const Identifier &

propertyName

)

const

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

operator[]() [4/4]

const var & var::operator[]

(

const char *

propertyName

)

const

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

getProperty()

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

noexcept

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

call() [1/6]

var var::call

(

const Identifier &

method

)

const

Invokes a named method call with no arguments.

call() [2/6]

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

Invokes a named method call with one argument.

call() [3/6]

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

Invokes a named method call with 2 arguments.

call() [4/6]

var 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 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 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.

invoke()

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

Invokes a named method call with a list of arguments.

getNativeFunction()

NativeFunction var::getNativeFunction

(

)

const

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

writeToStream()

void 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

readFromStream()

static var 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

---

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

• juce_Variant.h