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• 句法
• 描述
• 范例
• 规范
• 浏览器兼容性
• 另请参阅
• 相关话题

静态 Reflect .getOwnPropertyDescriptor() method is similar to Object.getOwnPropertyDescriptor() . It returns a property descriptor of the given property if it exists on the object, undefined 否则。

The source for this interactive example is stored in a GitHub repository. If you'd like to contribute to the interactive examples project, please clone https://github.com/mdn/interactive-examples and send us a pull request.

句法

Reflect.getOwnPropertyDescriptor(target, propertyKey)
					

参数

target

The target object in which to look for the property.

propertyKey

The name of the property to get an own property descriptor for.

返回值

A property descriptor object if the property exists in target object; otherwise, undefined .

异常

A TypeError , if target is not an Object .

描述

Reflect.getOwnPropertyDescriptor method returns a property descriptor of the given property if it exists in the target 对象， undefined otherwise. The only difference to Object.getOwnPropertyDescriptor() is how non-object targets are handled.

范例

使用 Reflect.getOwnPropertyDescriptor()

Reflect.getOwnPropertyDescriptor({x: 'hello'}, 'x')
// {value: "hello", writable: true, enumerable: true, configurable: true}
Reflect.getOwnPropertyDescriptor({x: 'hello'}, 'y')
// undefined
Reflect.getOwnPropertyDescriptor([], 'length')
// {value: 0, writable: true, enumerable: false, configurable: false}
					

Difference to Object.getOwnPropertyDescriptor()

若 target argument to this method is not an object (a primitive), then it will cause a TypeError . With Object.getOwnPropertyDescriptor , a non-object first argument will be coerced to an object at first.

Reflect.getOwnPropertyDescriptor('foo', 0)
// TypeError: "foo" is not non-null object
Object.getOwnPropertyDescriptor('foo', 0)
// { value: "f", writable: false, enumerable: true, configurable: false }
					

规范

规范
ECMAScript (ECMA-262) The definition of 'Reflect.getOwnPropertyDescriptor' in that specification.

浏览器兼容性

The compatibility table on this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request. 更新 GitHub 上的兼容性数据

	Desktop						Mobile						Server
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet	Node.js
getOwnPropertyDescriptor	Chrome 49	Edge 12	Firefox 42	IE No	Opera 36	Safari 10	WebView Android 49	Chrome Android 49	Firefox Android 42	Opera Android 36	Safari iOS 10	Samsung Internet Android 5.0	nodejs 6.0.0

图例

完整支持

完整支持

不支持

不支持

另请参阅

• Reflect
• Object.getOwnPropertyDescriptor()

元数据

• 最后修改： Jan 15, 2020

相关话题

1. 标准内置对象
2. Reflect
3. 方法
   1. Reflect.apply()
   2. Reflect.construct()
   3. Reflect.defineProperty()
   4. Reflect.deleteProperty()
   5. Reflect.get()
   6. Reflect.getOwnPropertyDescriptor()
   7. Reflect.getPrototypeOf()
   8. Reflect.has()
   9. Reflect.isExtensible()
   10. Reflect.ownKeys()
   11. Reflect.preventExtensions()
   12. Reflect.set()
   13. Reflect.setPrototypeOf()
4. 继承：
5. Object
6. 特性
   1. Object.prototype.__proto__
   2. Object.prototype.constructor
7. 方法
   1. Object.prototype.__defineGetter__()
   2. Object.prototype.__defineSetter__()
   3. Object.prototype.__lookupGetter__()
   4. Object.prototype.__lookupSetter__()
   5. Object.prototype.hasOwnProperty()
   6. Object.prototype.isPrototypeOf()
   7. Object.prototype.propertyIsEnumerable()
   8. Object.prototype.toLocaleString()
   9. Object.prototype.toSource()
   10. Object.prototype.toString()
   11. Object.prototype.valueOf()
   12. Object.setPrototypeOf()