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node_modules/node-addon-api/doc/value.md

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+# Value
+
+`Napi::Value` is the C++ manifestation of a JavaScript value. It is the base
+class upon which other JavaScript values such as `Napi::Number`,
+`Napi::Boolean`, `Napi::String`, and `Napi::Object` are based. It represents a
+JavaScript value of an unknown type. It is a thin wrapper around the N-API
+datatype `napi_value`. Methods on this class can be used to check the JavaScript
+type of the underlying N-API `napi_value` and also to convert to C++ types.
+
+## Constructors
+
+### Empty Constructor
+
+```cpp
+Napi::Value::Value();
+```
+
+Creates a new *empty* `Napi::Value` instance.
+
+### Constructor
+
+```cpp
+Napi::Value::Value(napi_env env, napi_value value);
+```
+
+- `[in] env`: The `napi_env` environment in which to construct the `Napi::Value`
+object.
+- `[in] value`: The C++ primitive from which to instantiate the `Napi::Value`.
+value` may be any of:
+  - `bool`
+  - Any integer type
+  - Any floating point type
+  - `const char*` (encoded using UTF-8, null-terminated)
+  - `const char16_t*` (encoded using UTF-16-LE, null-terminated)
+  - `std::string` (encoded using UTF-8)
+  - `std::u16string`
+  - `Napi::Value`
+  - `napi_value`
+
+## Operators
+
+### operator napi_value
+
+```cpp
+Napi::Value::operator napi_value() const;
+```
+
+Returns the underlying N-API `napi_value`. If the instance is _empty_, this
+returns `nullptr`.
+
+### operator ==
+
+```cpp
+bool Napi::Value::operator ==(const Napi::Value& other) const;
+```
+
+Returns `true` if this value strictly equals another value, or `false`
+otherwise.
+
+### operator !=
+
+```cpp
+bool Napi::Value::operator !=(const Napi::Value& other) const;
+```
+
+Returns `false` if this value strictly equals another value, or `true`
+otherwise.
+
+## Methods
+
+### As
+
+```cpp
+template <typename T> T Napi::Value::As() const;
+```
+
+Casts to another type of `Napi::Value`, when the actual type is known or
+assumed.
+
+This conversion does not coerce the type. Calling any methods inappropriate for
+the actual value type will throw `Napi::Error`.
+
+### Env
+
+```cpp
+Napi::Env Napi::Value::Env() const;
+```
+
+Returns the `Napi::Env` environment this value is associated with. See
+[`Napi::Env`](env.md) for more details about environments.
+
+### From
+
+```cpp
+template <typename T>
+static Napi::Value Napi::Value::From(napi_env env, const T& value);
+```
+
+- `[in] env`: The `napi_env` environment in which to create the `Napi::Value`
+object.
+- `[in] value`: The N-API primitive value from which to create the `Napi::Value`
+object.
+
+Returns a `Napi::Value` object from an N-API primitive value.
+
+This method is used to convert from a C++ type to a JavaScript value.
+Here, `value` may be any of:
+- `bool` - returns a `Napi::Boolean`.
+- Any integer type - returns a `Napi::Number`.
+- Any floating point type - returns a `Napi::Number`.
+- `const char*` (encoded using UTF-8, null-terminated) - returns a
+`Napi::String`.
+- `const char16_t*` (encoded using UTF-16-LE, null-terminated) - returns a
+`Napi::String`.
+- `std::string` (encoded using UTF-8) - returns a `Napi::String`.
+- `std::u16string` - returns a `Napi::String`.
+- `Napi::Value` - returns a `Napi::Value`.
+- `Napi_value` - returns a `Napi::Value`.
+
+### IsArray
+
+```cpp
+bool Napi::Value::IsArray() const;
+```
+
+Returns `true` if the underlying value is a JavaScript `Napi::Array` or `false`
+otherwise.
+
+### IsArrayBuffer
+
+```cpp
+bool Napi::Value::IsArrayBuffer() const;
+```
+
+Returns `true` if the underlying value is a JavaScript `Napi::ArrayBuffer` or
+`false` otherwise.
+
+### IsBoolean
+
+```cpp
+bool Napi::Value::IsBoolean() const;
+```
+
+Returns `true` if the underlying value is a JavaScript `true` or JavaScript
+`false`, or `false` if the value is not a `Napi::Boolean` value in JavaScript.
+
+### IsBuffer
+
+```cpp
+bool Napi::Value::IsBuffer() const;
+```
+
+Returns `true` if the underlying value is a Node.js `Napi::Buffer` or `false`
+otherwise.
+
+### IsDataView
+```cpp
+bool Napi::Value::IsDataView() const;
+```
+
+Returns `true` if the underlying value is a JavaScript `Napi::DataView` or
+`false` otherwise.
+
+### IsDate
+
+```cpp
+bool Napi::Value::IsDate() const;
+```
+
+Returns `true` if the underlying value is a JavaScript `Date` or `false`
+otherwise.
+
+### IsEmpty
+
+```cpp
+bool Napi::Value::IsEmpty() const;
+```
+
+Returns `true` if the value is uninitialized.
+
+An empty `Napi::Value` is invalid, and most attempts to perform an operation on
+an empty `Napi::Value` will result in an exception. An empty `Napi::Value` is
+distinct from JavaScript `null` or `undefined`, which are valid values.
+
+When C++ exceptions are disabled at compile time, a method with a `Napi::Value`
+return type may return an empty `Napi::Value` to indicate a pending exception.
+Thus, when C++ exceptions are not being used, callers should check the result of
+`Env::IsExceptionPending` before attempting to use the value.
+
+### IsExternal
+```cpp
+bool Napi::Value::IsExternal() const;
+```
+
+Returns `true` if the underlying value is a N-API external object or `false`
+otherwise.
+
+### IsFunction
+
+```cpp
+bool Napi::Value::IsFunction() const;
+```
+
+Returns `true` if the underlying value is a JavaScript `Napi::Function` or
+`false` otherwise.
+
+### IsNull
+
+```cpp
+bool Napi::Value::IsNull() const;
+```
+
+Returns `true` if the underlying value is a JavaScript `null` or `false`
+otherwise.
+
+### IsNumber
+
+```cpp
+bool Napi::Value::IsNumber() const;
+```
+
+Returns `true` if the underlying value is a JavaScript `Napi::Number` or `false`
+otherwise.
+
+### IsObject
+
+```cpp
+bool Napi::Value::IsObject() const;
+```
+
+Returns `true` if the underlying value is a JavaScript `Napi::Object` or `false`
+otherwise.
+
+### IsPromise
+
+```cpp
+bool Napi::Value::IsPromise() const;
+```
+
+Returns `true` if the underlying value is a JavaScript `Napi::Promise` or
+`false` otherwise.
+
+### IsString
+
+```cpp
+bool Napi::Value::IsString() const;
+```
+
+Returns `true` if the underlying value is a JavaScript `Napi::String` or `false`
+otherwise.
+
+### IsSymbol
+
+```cpp
+bool Napi::Value::IsSymbol() const;
+```
+
+Returns `true` if the underlying value is a JavaScript `Napi::Symbol` or `false`
+otherwise.
+
+### IsTypedArray
+
+```cpp
+bool Napi::Value::IsTypedArray() const;
+```
+
+Returns `true` if the underlying value is a JavaScript `Napi::TypedArray` or
+`false` otherwise.
+
+### IsUndefined
+
+```cpp
+bool Napi::Value::IsUndefined() const;
+```
+
+Returns `true` if the underlying value is a JavaScript `undefined` or `false`
+otherwise.
+
+### StrictEquals
+
+```cpp
+bool Napi::Value::StrictEquals(const Napi::Value& other) const;
+```
+- `[in] other`: The `Napi::Value` object to be compared.
+
+Returns a `bool` indicating if this `Napi::Value` strictly equals another
+`Napi::Value`.
+
+### ToBoolean
+
+```cpp
+Napi::Boolean Napi::Value::ToBoolean() const;
+```
+
+Returns a `Napi::Boolean` representing the `Napi::Value`.
+
+This is a wrapper around `napi_coerce_to_boolean`. This will throw a JavaScript
+exception if the coercion fails. If C++ exceptions are not being used, callers
+should check the result of `Env::IsExceptionPending` before attempting to use
+the returned value.
+
+### ToNumber
+
+```cpp
+Napi::Number Napi::Value::ToNumber() const;
+```
+
+Returns the `Napi::Value` coerced to a JavaScript number.
+
+### ToObject
+
+```cpp
+Napi::Object Napi::Value::ToObject() const;
+```
+
+Returns the `Napi::Value` coerced to a JavaScript object.
+
+### ToString
+
+```cpp
+Napi::String Napi::Value::ToString() const;
+```
+
+Returns the `Napi::Value` coerced to a JavaScript string.
+
+### Type
+
+```cpp
+napi_valuetype Napi::Value::Type() const;
+```
+
+Returns the `napi_valuetype` type of the `Napi::Value`.
+
+[`Napi::Boolean`]: ./boolean.md
+[`Napi::BigInt`]: ./bigint.md
+[`Napi::Date`]: ./date.md
+[`Napi::External`]: ./external.md
+[`Napi::Name`]: ./name.md
+[`Napi::Number`]: ./number.md
+[`Napi::Object`]: ./object.md