3.6 KiB
Number
Napi::Number class is a representation of the JavaScript
Number object. The Napi::Number class inherits
its behavior from Napi::Value class (for more info see Napi::Value)
Methods
Constructor
Creates a new empty instance of a Napi::Number
object.
Napi::Number();Returns a new empty Napi::Number object.
Contructor
Creates a new instance of a Napi::Number object.
Napi::Number(napi_env env, napi_value value);[in] env: Thenapi_envenvironment in which to construct theNapi::Numberobject.[in] value: The JavaScript value holding a number.
Returns a non-empty Napi::Number object.
### New
Creates a new instance of a Napi::Number object.
Napi::Number Napi::Number::New(napi_env env, double value);[in] env: Thenapi_envenvironment in which to construct theNapi::Numberobject.[in] value: The C++ primitive from which to instantiate theNapi::Number.
Creates a new instance of a Napi::Number object.
Int32Value
Converts a Napi::Number value to a int32_t
primitive type.
Napi::Number::Int32Value() const;Returns the int32_t primitive type of the corresponding
Napi::Number object.
Uint32Value
Converts a Napi::Number value to a uint32_t
primitive type.
Napi::Number::Uint32Value() const;Returns the uint32_t primitive type of the corresponding
Napi::Number object.
Int64Value
Converts a Napi::Number value to a int64_t
primitive type.
Napi::Number::Int64Value() const;Returns the int64_t primitive type of the corresponding
Napi::Number object.
FloatValue
Converts a Napi::Number value to a float
primitive type.
Napi::Number::FloatValue() const;Returns the float primitive type of the corresponding
Napi::Number object.
DoubleValue
Converts a Napi::Number value to a double
primitive type.
Napi::Number::DoubleValue() const;Returns the double primitive type of the corresponding
Napi::Number object.
Operators
The Napi::Number class contains a set of operators to
easily cast JavaScript Number object to one of the
following primitive types:
int32_tuint32_tint64_tfloatdouble
operator int32_t
Converts a Napi::Number value to a int32_t
primitive.
Napi::Number::operator int32_t() const;Returns the int32_t primitive type of the corresponding
Napi::Number object.
operator uint32_t
Converts a Napi::Number value to a uint32_t
primitive type.
Napi::Number::operator uint32_t() const;Returns the uint32_t primitive type of the corresponding
Napi::Number object.
operator int64_t
Converts a Napi::Number value to a int64_t
primitive type.
Napi::Number::operator int64_t() const;Returns the int64_t primitive type of the corresponding
Napi::Number object.
operator float
Converts a Napi::Number value to a float
primitive type.
Napi::Number::operator float() const;Returns the float primitive type of the corresponding
Napi::Number object.
operator double
Converts a Napi::Number value to a double
primitive type.
Napi::Number::operator double() const;Returns the double primitive type of the corresponding
Napi::Number object.
Example
The following shows an example of casting a number to an
uint32_t value.
uint32_t operatorVal = Napi::Number::New(Env(), 10.0); // Number to unsigned 32 bit integer
// or
auto instanceVal = info[0].As<Napi::Number>().Uint32Value();