class QJSPrimitiveValue¶

The QJSPrimitiveValue class operates on primitive types in JavaScript semantics. More…

Synopsis¶

Methods¶

def __init__()
def constData()
def data()
def equals()
def metaType()
def __ne__()
def __mod__()
def __mul__()
def __add__()
def __iadd__()
def __sub__()
def __isub__()
def __div__()
def __lt__()
def __le__()
def __eq__()
def __gt__()
def __ge__()
def strictlyEquals()
def toBoolean()
def toDouble()
def toInteger()
def toString()
def toVariant()
def type()

Note

This documentation may contain snippets that were automatically translated from C++ to Python. We always welcome contributions to the snippet translation. If you see an issue with the translation, you can also let us know by creating a ticket on https:/bugreports.qt.io/projects/PYSIDE

Detailed Description¶

QJSPrimitiveValue supports most of the primitive types defined in the ECMA-262 standard, in particular Undefined, Boolean, Number, and String. Additionally, you can store a JavaScript null in a QJSPrimitiveValue and as a special case of Number, you can store an integer value.

All those values are stored immediately, without interacting with the JavaScript heap. Therefore, you can pass QJSPrimitiveValues between different JavaScript engines. In contrast to QJSManagedValue , there is also no danger in destroying a QJSPrimitiveValue from a different thread than it was created in. On the flip side, QJSPrimitiveValue does not hold a reference to any JavaScript engine.

QJSPrimitiveValue implements the JavaScript arithmetic and comparison operators on the supported types in JavaScript semantics. Types are coerced like the JavaScript engine would coerce them if the operators were written in a JavaScript expression.

The JavaScript Symbol type is not supported as it is of very limited utility regarding arithmetic and comparison operators, the main purpose of QJSPrimitiveValue . In particular, it causes an exception whenever you try to coerce it to a number or a string, and we cannot throw exceptions without a JavaScript Engine.

class Type¶

This enum speicifies the types a QJSPrimitiveValue might contain.

Constant

Description

QJSPrimitiveValue.Undefined

The JavaScript Undefined value.

QJSPrimitiveValue.Null

The JavaScript null value. This is in fact not a separate JavaScript type but a special value of the Object type. As it is very common and storable without JavaScript engine, it is still supported.

QJSPrimitiveValue.Boolean

A JavaScript Boolean value.

QJSPrimitiveValue.Integer

An integer. This is a special case of the JavaScript Number type. JavaScript does not have an actual integer type, but the ECMA-262 standard contains rules on how to transform a Number in order to prepare it for certain operators that only make sense on integers, in particular the bit shift operators. QJSPrimitiveValue ‘s Integer type represents the result of such a transformation.

QJSPrimitiveValue.Double

A JavaScript Number value.

QJSPrimitiveValue.String

A JavaScript String value.

Constant	Description
QJSPrimitiveValue.Undefined	The JavaScript Undefined value.
QJSPrimitiveValue.Null	The JavaScript null value. This is in fact not a separate JavaScript type but a special value of the Object type. As it is very common and storable without JavaScript engine, it is still supported.
QJSPrimitiveValue.Boolean	A JavaScript Boolean value.
QJSPrimitiveValue.Integer	An integer. This is a special case of the JavaScript Number type. JavaScript does not have an actual integer type, but the ECMA-262 standard contains rules on how to transform a Number in order to prepare it for certain operators that only make sense on integers, in particular the bit shift operators. `QJSPrimitiveValue` ‘s Integer type represents the result of such a transformation.
QJSPrimitiveValue.Double	A JavaScript Number value.
QJSPrimitiveValue.String	A JavaScript String value.

__init__()¶

Creates a QJSPrimitiveValue of type Undefined.

__init__(type)

Parameters:: type – QMetaType

__init__(string)

Parameters:: string – str

Creates a QJSPrimitiveValue of value value and type String.

__init__(value)

Parameters:: value – bool

Creates a QJSPrimitiveValue of value value and type Boolean.

__init__(variant)

Parameters:: variant – object

Creates a QJSPrimitiveValue from the contents of value if those contents can be stored in QJSPrimtiveValue. Otherwise this results in a QJSPrimitiveValue of type Undefined.

__init__(value)

Parameters:: value – float

Creates a QJSPrimitiveValue of value value and type Double.

__init__(value)

Parameters:: value – int

Creates a QJSPrimitiveValue of value value and type Integer.

__init__(type, value)

Parameters:

type – QMetaType
value – void

Creates a QJSPrimitiveValue of type type, and initializes with value if type can be stored in QJSPrimtiveValue. value must not be nullptr in that case. If type cannot be stored this results in a QJSPrimitiveValue of type Undefined.

Note that you have to pass the address of the variable you want stored.

Usually, you never have to use this constructor, use the one taking QVariant instead.

constData()¶

Return type:: void

data()¶

Return type:: void

equals(other)¶

Parameters:: other – QJSPrimitiveValue
Return type:: bool

Performs the JavaScript ‘==’ operation on this QJSPrimitiveValue and other, and returns the result.

metaType()¶

Return type:: QMetaType

Returns the QMetaType of the value stored in the QJSPrimitiveValue .

__ne__(rhs)¶

Parameters:: rhs – QJSPrimitiveValue
Return type:: bool

Performs the JavaScript ‘!==’ operation on lhs and rhs, and returns the result.

__mod__(rhs)¶

Parameters:: rhs – QJSPrimitiveValue
Return type:: QJSPrimitiveValue

__mul__(rhs)¶

Parameters:: rhs – QJSPrimitiveValue
Return type:: QJSPrimitiveValue

Performs the JavaScript ‘*’ operation on lhs and rhs, and returns the result.

__add__()¶

Return type:: QJSPrimitiveValue

__add__(rhs)

Parameters:: rhs – QJSPrimitiveValue
Return type:: QJSPrimitiveValue

Perfoms the JavaScript ‘+’ operation on lhs and rhs, and returns the result.

__iadd__()¶

Return type:: QJSPrimitiveValue

__iadd__(arg__1)

Parameters:: arg__1 – int
Return type:: QJSPrimitiveValue

__sub__()¶

Return type:: QJSPrimitiveValue

__sub__(rhs)

Parameters:: rhs – QJSPrimitiveValue
Return type:: QJSPrimitiveValue

Performs the JavaScript ‘-’ operation on lhs and rhs, and returns the result.

__isub__()¶

Return type:: QJSPrimitiveValue

__isub__(arg__1)

Parameters:: arg__1 – int
Return type:: QJSPrimitiveValue

__div__(rhs)¶

Parameters:: rhs – QJSPrimitiveValue
Return type:: QJSPrimitiveValue

Performs the JavaScript ‘/’ operation between lhs and rhs, and returns the result.

__lt__(rhs)¶

Parameters:: rhs – QJSPrimitiveValue
Return type:: bool

Performs the JavaScript ‘<’ operation on lhs and rhs, and returns the result.

__le__(rhs)¶

Parameters:: rhs – QJSPrimitiveValue
Return type:: bool

Performs the JavaScript ‘<=’ operation on lhs and rhs, and returns the result.

__eq__(rhs)¶

Parameters:: rhs – QJSPrimitiveValue
Return type:: bool

Performs the JavaScript ‘===’ operation on lhs and rhs, and returns the result.

__gt__(rhs)¶

Parameters:: rhs – QJSPrimitiveValue
Return type:: bool

Performs the JavaScript ‘>’ operation on lhs and rhs, and returns the result.

__ge__(rhs)¶

Parameters:: rhs – QJSPrimitiveValue
Return type:: bool

Performs the JavaScript ‘>=’ operation on lhs and rhs, and returns the result.

strictlyEquals(other)¶

Parameters:: other – QJSPrimitiveValue
Return type:: bool

Performs the JavaScript ‘===’ operation on this QJSPrimitiveValue and other, and returns the result.

toBoolean()¶

Return type:: bool

Returns the value coerced a boolean by JavaScript rules.

toDouble()¶

Return type:: float

Returns the value coerced to a JavaScript Number by JavaScript rules.

toInteger()¶

Return type:: int

Returns the value coerced to an integral 32bit number by the rules JavaScript would apply when preparing it for a bit shift operation.

toString()¶

Return type:: str

Returns the value coerced to a JavaScript String by JavaScript rules.

toVariant()¶

Return type:: object

type()¶

Return type:: Type

Returns the type of the QJSPrimitiveValue .