## New NAN provides a `Nan::New()` helper for the creation of new JavaScript objects in a way that's compatible across the supported versions of V8. - Nan::New() - Nan::Undefined() - Nan::Null() - Nan::True() - Nan::False() - Nan::EmptyString() ### Nan::New() `Nan::New()` should be used to instantiate new JavaScript objects. Refer to the specific V8 type in the [V8 documentation](https://v8docs.nodesource.com/io.js-3.0/d1/d83/classv8_1_1_data.html) for information on the types of arguments required for instantiation. Signatures: Return types are mostly omitted from the signatures for simplicity. In most cases the type will be contained within a `v8::Local`. The following types will be contained within a `Nan::MaybeLocal`: `v8::String`, `v8::Date`, `v8::RegExp`, `v8::Script`, `v8::UnboundScript`. Empty objects: ```c++ Nan::New(); ``` Generic single and multiple-argument: ```c++ Nan::New(A0 arg0); Nan::New(A0 arg0, A1 arg1); Nan::New(A0 arg0, A1 arg1, A2 arg2); Nan::New(A0 arg0, A1 arg1, A2 arg2, A3 arg3); ``` For creating `v8::FunctionTemplate` and `v8::Function` objects: _The definition of `Nan::FunctionCallback` can be found in the [Method declaration](./methods.md#api_nan_method) documentation._ ```c++ Nan::New(Nan::FunctionCallback callback, v8::Local data = v8::Local()); Nan::New(Nan::FunctionCallback callback, v8::Local data = v8::Local(), A2 a2 = A2()); ``` Native types: ```c++ v8::Local Nan::New(bool value); v8::Local Nan::New(int32_t value); v8::Local Nan::New(uint32_t value); v8::Local Nan::New(double value); v8::Local Nan::New(std::string const& value); v8::Local Nan::New(const char * value, int length); v8::Local Nan::New(const char * value); v8::Local Nan::New(const uint16_t * value); ``` Specialized types: ```c++ v8::Local Nan::New(v8::String::ExternalStringResource * value); v8::Local Nan::New(Nan::ExternalOneByteStringResource * value); v8::Local Nan::New(v8::Local pattern, v8::RegExp::Flags flags); ``` Note that `Nan::ExternalOneByteStringResource` maps to [`v8::String::ExternalOneByteStringResource`](https://v8docs.nodesource.com/io.js-3.0/d9/db3/classv8_1_1_string_1_1_external_one_byte_string_resource.html), and `v8::String::ExternalAsciiStringResource` in older versions of V8. ### Nan::Undefined() A helper method to reference the `v8::Undefined` object in a way that is compatible across all supported versions of V8. Signature: ```c++ v8::Local Nan::Undefined() ``` ### Nan::Null() A helper method to reference the `v8::Null` object in a way that is compatible across all supported versions of V8. Signature: ```c++ v8::Local Nan::Null() ``` ### Nan::True() A helper method to reference the `v8::Boolean` object representing the `true` value in a way that is compatible across all supported versions of V8. Signature: ```c++ v8::Local Nan::True() ``` ### Nan::False() A helper method to reference the `v8::Boolean` object representing the `false` value in a way that is compatible across all supported versions of V8. Signature: ```c++ v8::Local Nan::False() ``` ### Nan::EmptyString() Call [`v8::String::Empty`](https://v8docs.nodesource.com/io.js-3.0/d2/db3/classv8_1_1_string.html#a7c1bc8886115d7ee46f1d571dd6ebc6d) to reference the empty string in a way that is compatible across all supported versions of V8. Signature: ```c++ v8::Local Nan::EmptyString() ``` ### Nan::NewOneByteString() An implementation of [`v8::String::NewFromOneByte()`](https://v8docs.nodesource.com/io.js-3.0/d2/db3/classv8_1_1_string.html#a5264d50b96d2c896ce525a734dc10f09) provided for consistent availability and API across supported versions of V8. Allocates a new string from Latin-1 data. Signature: ```c++ Nan::MaybeLocal Nan::NewOneByteString(const uint8_t * value, int length = -1) ```