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.

Constructor

Creates a new instance of a Napi::Number object.

Napi::Number(napi_env env, napi_value value);

• [in] env: The napi_env environment in which to construct the Napi::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.

Napi::Number Napi::Number::New(napi_env env, double value);

• [in] env: The napi_env environment in which to construct the Napi::Number object.
• [in] value: The C++ primitive from which to instantiate the Napi::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_t
• uint32_t
• int64_t
• float
• double

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();