juce::var Class Reference

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

#include "juce_Variant.h"

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

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.

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}

Definition at line 41 of file juce_Variant.h.

Member Typedef Documentation

NativeFunction

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

Definition at line 57 of file juce_Variant.h.

Constructor & Destructor Documentation

var() [1/19]

juce::var::var ( )

noexcept

Creates a void variant.

Definition at line 497 of file juce_Variant.cpp.

~var()

juce::var::~var ( )

noexcept

Destructor.

Definition at line 499 of file juce_Variant.cpp.

var() [2/19]

juce::var::var

(

const var &

valueToCopy

)

Definition at line 502 of file juce_Variant.cpp.

var() [3/19]

juce::var::var ( int  value )

noexcept

Definition at line 507 of file juce_Variant.cpp.

var() [4/19]

juce::var::var ( int64  value )

noexcept

Definition at line 508 of file juce_Variant.cpp.

var() [5/19]

juce::var::var ( bool  value )

noexcept

Definition at line 509 of file juce_Variant.cpp.

var() [6/19]

juce::var::var ( double  value )

noexcept

Definition at line 510 of file juce_Variant.cpp.

var() [7/19]

juce::var::var

(

const char *

value

)

Definition at line 514 of file juce_Variant.cpp.

var() [8/19]

juce::var::var

(

const wchar_t *

value

)

Definition at line 515 of file juce_Variant.cpp.

var() [9/19]

juce::var::var

(

const String &

value

)

Definition at line 513 of file juce_Variant.cpp.

var() [10/19]

juce::var::var

(

const Array< var > &

value

)

Definition at line 512 of file juce_Variant.cpp.

var() [11/19]

juce::var::var

(

const StringArray &

value

)

Definition at line 519 of file juce_Variant.cpp.

var() [12/19]

juce::var::var

(

ReferenceCountedObject *

object

)

Definition at line 530 of file juce_Variant.cpp.

var() [13/19]

juce::var::var ( NativeFunction  method )

noexcept

Definition at line 511 of file juce_Variant.cpp.

var() [14/19]

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

Definition at line 516 of file juce_Variant.cpp.

var() [15/19]

juce::var::var

(

const MemoryBlock &

binaryData

)

Definition at line 517 of file juce_Variant.cpp.

var() [16/19]

juce::var::var ( var &&  other )

noexcept

Definition at line 585 of file juce_Variant.cpp.

var() [17/19]

juce::var::var

(

String &&

v

)

Definition at line 598 of file juce_Variant.cpp.

var() [18/19]

juce::var::var

(

MemoryBlock &&

v

)

Definition at line 603 of file juce_Variant.cpp.

var() [19/19]

juce::var::var

(

Array< var > &&

v

)

Definition at line 608 of file juce_Variant.cpp.

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>.

Definition at line 791 of file juce_Variant.cpp.

call() [1/6]

var juce::var::call

(

const Identifier &

method

)

const

Invokes a named method call with no arguments.

Definition at line 712 of file juce_Variant.cpp.

call() [2/6]

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

Invokes a named method call with one argument.

Definition at line 717 of file juce_Variant.cpp.

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.

Definition at line 722 of file juce_Variant.cpp.

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.

Definition at line 728 of file juce_Variant.cpp.

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.

Definition at line 734 of file juce_Variant.cpp.

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.

Definition at line 740 of file juce_Variant.cpp.

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).

Definition at line 664 of file juce_Variant.cpp.

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

Definition at line 622 of file juce_Variant.cpp.

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

Definition at line 627 of file juce_Variant.cpp.

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!

Definition at line 561 of file juce_Variant.cpp.

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!

Definition at line 562 of file juce_Variant.cpp.

getDynamicObject()

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

noexcept

Definition at line 563 of file juce_Variant.cpp.

getNativeFunction()

var::NativeFunction juce::var::getNativeFunction

(

)

const

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

Definition at line 699 of file juce_Variant.cpp.

getObject()

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

noexcept

Definition at line 560 of file juce_Variant.cpp.

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.

Definition at line 683 of file juce_Variant.cpp.

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.

Definition at line 691 of file juce_Variant.cpp.

hasSameTypeAs()

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

noexcept

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

Definition at line 632 of file juce_Variant.cpp.

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.

Definition at line 812 of file juce_Variant.cpp.

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>.

Definition at line 802 of file juce_Variant.cpp.

invoke()

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

Invokes a named method call with a list of arguments.

Definition at line 704 of file juce_Variant.cpp.

isArray()

bool juce::var::isArray ( ) const

noexcept

Definition at line 549 of file juce_Variant.cpp.

isBinaryData()

bool juce::var::isBinaryData ( ) const

noexcept

Definition at line 550 of file juce_Variant.cpp.

isBool()

bool juce::var::isBool ( ) const

noexcept

Definition at line 545 of file juce_Variant.cpp.

isDouble()

bool juce::var::isDouble ( ) const

noexcept

Definition at line 546 of file juce_Variant.cpp.

isInt()

bool juce::var::isInt ( ) const

noexcept

Definition at line 543 of file juce_Variant.cpp.

isInt64()

bool juce::var::isInt64 ( ) const

noexcept

Definition at line 544 of file juce_Variant.cpp.

isMethod()

bool juce::var::isMethod ( ) const

noexcept

Definition at line 551 of file juce_Variant.cpp.

isObject()

bool juce::var::isObject ( ) const

noexcept

Definition at line 548 of file juce_Variant.cpp.

isString()

bool juce::var::isString ( ) const

noexcept

Definition at line 547 of file juce_Variant.cpp.

isUndefined()

bool juce::var::isUndefined ( ) const

noexcept

Definition at line 542 of file juce_Variant.cpp.

isVoid()

bool juce::var::isVoid ( ) const

noexcept

Definition at line 541 of file juce_Variant.cpp.

operator bool()

juce::var::operator bool ( ) const

noexcept

Definition at line 555 of file juce_Variant.cpp.

operator double()

juce::var::operator double ( ) const

noexcept

Definition at line 557 of file juce_Variant.cpp.

operator float()

juce::var::operator float ( ) const

noexcept

Definition at line 556 of file juce_Variant.cpp.

operator int()

juce::var::operator int ( ) const

noexcept

Definition at line 553 of file juce_Variant.cpp.

operator int64()

juce::var::operator int64 ( ) const

noexcept

Definition at line 554 of file juce_Variant.cpp.

operator String()

juce::var::operator String

(

)

const

Definition at line 559 of file juce_Variant.cpp.

operator=() [1/14]

var & juce::var::operator=

(

bool

value

)

Definition at line 575 of file juce_Variant.cpp.

operator=() [2/14]

var & juce::var::operator=

(

const Array< var > &

value

)

Definition at line 581 of file juce_Variant.cpp.

operator=() [3/14]

var & juce::var::operator=

(

const char *

value

)

Definition at line 577 of file juce_Variant.cpp.

operator=() [4/14]

var & juce::var::operator=

(

const MemoryBlock &

value

)

Definition at line 580 of file juce_Variant.cpp.

operator=() [5/14]

var & juce::var::operator=

(

const String &

value

)

Definition at line 579 of file juce_Variant.cpp.

operator=() [6/14]

var & juce::var::operator=

(

const var &

valueToCopy

)

Definition at line 572 of file juce_Variant.cpp.

operator=() [7/14]

var & juce::var::operator=

(

const wchar_t *

value

)

Definition at line 578 of file juce_Variant.cpp.

operator=() [8/14]

var & juce::var::operator=

(

double

value

)

Definition at line 576 of file juce_Variant.cpp.

operator=() [9/14]

var & juce::var::operator=

(

int

value

)

Definition at line 573 of file juce_Variant.cpp.

operator=() [10/14]

var & juce::var::operator=

(

int64

value

)

Definition at line 574 of file juce_Variant.cpp.

operator=() [11/14]

var & juce::var::operator=

(

NativeFunction

method

)

Definition at line 583 of file juce_Variant.cpp.

operator=() [12/14]

var & juce::var::operator=

(

ReferenceCountedObject *

object

)

Definition at line 582 of file juce_Variant.cpp.

operator=() [13/14]

var & juce::var::operator=

(

String &&

v

)

Definition at line 613 of file juce_Variant.cpp.

operator=() [14/14]

var & juce::var::operator= ( var &&  other )

noexcept

Definition at line 592 of file juce_Variant.cpp.

operator[]() [1/4]

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

(

const char *

propertyName

)

const

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

Definition at line 678 of file juce_Variant.cpp.

operator[]() [2/4]

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

(

const Identifier &

propertyName

)

const

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

Definition at line 670 of file juce_Variant.cpp.

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>.

Definition at line 766 of file juce_Variant.cpp.

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>.

Definition at line 755 of file juce_Variant.cpp.

readFromStream()

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

Definition at line 826 of file juce_Variant.cpp.

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>.

Definition at line 796 of file juce_Variant.cpp.

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>.

Definition at line 807 of file juce_Variant.cpp.

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.

Definition at line 747 of file juce_Variant.cpp.

swapWith()

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

noexcept

Definition at line 566 of file juce_Variant.cpp.

toString()

String juce::var::toString

(

)

const

Definition at line 558 of file juce_Variant.cpp.

undefined()

var juce::var::undefined ( )

staticnoexcept

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

Definition at line 538 of file juce_Variant.cpp.

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

Definition at line 821 of file juce_Variant.cpp.

Friends And Related Symbol Documentation

canCompare

bool canCompare ( const var &  v1, const var &  v2  )

friend

Definition at line 637 of file juce_Variant.cpp.

---

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

• juce_core/containers/juce_Variant.h
• juce_core/containers/juce_Variant.cpp