Object.getOwnPropertyDescriptors() - JavaScript 编辑

The Object.getOwnPropertyDescriptors() method returns all own property descriptors of a given object.

Syntax

Object.getOwnPropertyDescriptors(obj)

Parameters

obj
The object for which to get all own property descriptors.

Return value

An object containing all own property descriptors of an object. Might be an empty object, if there are no properties.

Description

This method permits examination of the precise description of all own properties of an object. A property in JavaScript consists of either a string-valued name or a Symbol and a property descriptor. Further information about property descriptor types and their attributes can be found in Object.defineProperty().

A property descriptor is a record with some of the following attributes:

value
The value associated with the property (data descriptors only).
writable
true if and only if the value associated with the property may be changed (data descriptors only).
get
A function which serves as a getter for the property, or undefined if there is no getter (accessor descriptors only).
set
A function which serves as a setter for the property, or undefined if there is no setter (accessor descriptors only).
configurable
true if and only if the type of this property descriptor may be changed and if the property may be deleted from the corresponding object.
enumerable
true if and only if this property shows up during enumeration of the properties on the corresponding object.

Examples

Creating a shallow clone

Whereas the Object.assign() method will only copy enumerable and own properties from a source object to a target object, you are able to use this method and Object.create() for a shallow copy between two unknown objects:

Object.create(
  Object.getPrototypeOf(obj),
  Object.getOwnPropertyDescriptors(obj)
);

Creating a subclass

A typical way of creating a subclass is to define the subclass, set its prototype to an instance of the superclass, and then define properties on that instance. This can get awkward especially for getters and setters. Instead, you can use this code to set the prototype:

function superclass() {}
superclass.prototype = {
  // Define your methods and properties here
};
function subclass() {}
subclass.prototype = Object.create(
  superclass.prototype,
  {
    // Define your methods and properties here
  }
);

Specifications

Specification
ECMAScript (ECMA-262)
The definition of 'Object.getOwnPropertyDescriptors' in that specification.

Browser compatibility

BCD tables only load in the browser

See also

如果你对这篇内容有疑问,欢迎到本站社区发帖提问 参与讨论,获取更多帮助,或者扫码二维码加入 Web 技术交流群。

扫码二维码加入Web技术交流群

发布评论

需要 登录 才能够评论, 你可以免费 注册 一个本站的账号。
列表为空,暂无数据

词条统计

浏览:100 次

字数:5796

最后编辑:7年前

编辑次数:0 次

    我们使用 Cookies 和其他技术来定制您的体验包括您的登录状态等。通过阅读我们的 隐私政策 了解更多相关信息。 单击 接受 或继续使用网站,即表示您同意使用 Cookies 和您的相关数据。
    原文