使用 JavaScript 值


¥Working with JavaScript values

Node-API 公开了一组 API 来创建所有类型的 JavaScript 值。其中一些类型记录在 ECMAScript 语言规范第 6 节 下。

¥Node-API exposes a set of APIs to create all types of JavaScript values. Some of these types are documented under Section 6 of the ECMAScript Language Specification.

从根本上说,这些 API 用于执行以下操作之一:

¥Fundamentally, these APIs are used to do one of the following:

  1. 创建一个新的 JavaScript 对象

    ¥Create a new JavaScript object

  2. 从原始 C 类型转换为 Node-API 值

    ¥Convert from a primitive C type to a Node-API value

  3. 从 Node-API 值转换为原始 C 类型

    ¥Convert from Node-API value to a primitive C type

  4. 获取全局实例包括 undefinednull

    ¥Get global instances including undefined and null

Node-API 值由类型 napi_value 表示。任何需要 JavaScript 值的 Node-API 调用都采用 napi_value。在某些情况下,API 会预先检查 napi_value 的类型。但是,为了获得更好的性能,调用者最好确保所讨论的 napi_value 是 API 期望的 JavaScript 类型。

¥Node-API values are represented by the type napi_value. Any Node-API call that requires a JavaScript value takes in a napi_value. In some cases, the API does check the type of the napi_value up-front. However, for better performance, it's better for the caller to make sure that the napi_value in question is of the JavaScript type expected by the API.