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.
::Number(); Napi
Returns a new empty Napi::Number
object.
Contructor
Creates a new instance of a Napi::Number
object.
::Number(napi_env env, napi_value value); Napi
[in] env
: Thenapi_env
environment in which to construct theNapi::Number
object.[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.
::Number Napi::Number::New(napi_env env, double value); Napi
[in] env
: Thenapi_env
environment in which to construct theNapi::Number
object.[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.
::Number::Int32Value() const; Napi
Returns the int32_t
primitive type of the corresponding
Napi::Number
object.
Uint32Value
Converts a Napi::Number
value to a uint32_t
primitive type.
::Number::Uint32Value() const; Napi
Returns the uint32_t
primitive type of the corresponding
Napi::Number
object.
Int64Value
Converts a Napi::Number
value to a int64_t
primitive type.
::Number::Int64Value() const; Napi
Returns the int64_t
primitive type of the corresponding
Napi::Number
object.
FloatValue
Converts a Napi::Number
value to a float
primitive type.
::Number::FloatValue() const; Napi
Returns the float
primitive type of the corresponding
Napi::Number
object.
DoubleValue
Converts a Napi::Number
value to a double
primitive type.
::Number::DoubleValue() const; Napi
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_t
uint32_t
int64_t
float
double
operator int32_t
Converts a Napi::Number
value to a int32_t
primitive.
::Number::operator int32_t() const; Napi
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.
::Number::operator uint32_t() const; Napi
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.
::Number::operator int64_t() const; Napi
Returns the int64_t
primitive type of the corresponding
Napi::Number
object.
operator float
Converts a Napi::Number
value to a float
primitive type.
::Number::operator float() const; Napi
Returns the float
primitive type of the corresponding
Napi::Number
object.
operator double
Converts a Napi::Number
value to a double
primitive type.
::Number::operator double() const; Napi
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();