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# 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`](value.md))
## Methods
### Constructor
Creates a new _empty_ instance of a `Napi::Number` object.
```cpp
Napi::Number();
```
Returns a new _empty_ `Napi::Number` object.
### Constructor
Creates a new instance of a `Napi::Number` object.
```cpp
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.
```cpp
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.
```cpp
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.
```cpp
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.
```cpp
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.
```cpp
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.
```cpp
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.
```cpp
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.
```cpp
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.
```cpp
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.
```cpp
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.
```cpp
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.
```cpp
uint32_t operatorVal = Napi::Number::New(Env(), 10.0); // Number to unsigned 32 bit integer
// or
auto instanceVal = info[0].As<Napi::Number>().Uint32Value();
```
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