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• 描述
• 静态方法
• 范例
• 规范
• 浏览器兼容性
• 另请参阅
• 相关话题

Reflect is a built-in object that provides methods for interceptable JavaScript operations. The methods are the same as those of proxy handlers . Reflect is not a function object, so it's not constructible.

描述

Unlike most global objects, Reflect is not a constructor. You cannot use it with a new operator or invoke the Reflect object as a function. All properties and methods of Reflect are static (just like the Math 对象)。

Reflect object provides the following static functions which have the same names as the proxy handler methods .

Some of these methods are also the same as corresponding methods on Object , although they do have some subtle differences between them.

静态方法

Reflect.apply( target , thisArgument , argumentsList )

Calls a target function with arguments as specified by the argumentsList parameter. See also Function.prototype.apply() .

Reflect.construct( target , argumentsList [, newTarget ])

new operator as a function. Equivalent to calling new target (... argumentsList ) . Also provides the option to specify a different prototype.

Reflect.defineProperty( target , propertyKey , attributes )

类似于 Object.defineProperty() . Returns a 布尔 也就是 true if the property was successfully defined.

Reflect.deleteProperty( target , propertyKey )

delete operator as a function. Equivalent to calling delete target [ propertyKey ] .

Reflect.get( target , propertyKey [, receiver ])

Returns the value of the property. Works like getting a property from an object ( target[propertyKey] ) as a function.

Reflect.getOwnPropertyDescriptor( target , propertyKey )

类似于 Object.getOwnPropertyDescriptor() . Returns a property descriptor of the given property if it exists on the object, undefined 否则。

Reflect.getPrototypeOf( target )

如同 Object.getPrototypeOf() .

Reflect.has( target, propertyKey )

返回 布尔 indicating whether the target has the property. Either as own or inherited. Works like the in operator as a function.

Reflect.isExtensible( target )

如同 Object.isExtensible() . Returns a 布尔 也就是 true if the target is extensible.

Reflect.ownKeys( target )

Returns an array of the target object's own (not inherited) property keys.

Reflect.preventExtensions( target )

类似于 Object.preventExtensions() . Returns a 布尔 也就是 true if the update was successful.

Reflect.set( target , propertyKey , value [, receiver ])

A function that assigns values to properties. Returns a 布尔 也就是 true if the update was successful.

Reflect.setPrototypeOf( target , prototype )

A function that sets the prototype of an object. Returns a 布尔 也就是 true if the update was successful.

范例

Detecting whether an object contains certain properties

const duck = {
  name: 'Maurice',
  color: 'white',
  greeting: function() {
    console.log(`Quaaaack! My name is ${this.name}`);
  }
}
Reflect.has(duck, 'color');
// true
Reflect.has(duck, 'haircut');
// false
					

Returning the object's own keys

Reflect.ownKeys(duck);
// [ "name", "color", "greeting" ]
					

Adding a new property to the object

Reflect.set(duck, 'eyes', 'black');
// returns "true" if successful
// "duck" now contains the property "eyes: 'black'"
					

规范

规范
ECMAScript (ECMA-262) The definition of 'Reflect' 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
Reflect	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
apply	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
construct	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
defineProperty	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
deleteProperty	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
get	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
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
getPrototypeOf	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
has	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
isExtensible	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
ownKeys	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
preventExtensions	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
set	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
setPrototypeOf	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

• Proxy global object.
• handler 对象。

元数据

• 最后修改： Jun 1, 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()