JS: Reflect Object

By Xah Lee. Date: 2016-12-01. Last updated: 2017-04-16.

New in ES2015.

Reflect is the value of the property key "Reflect" of the global object.

console.log ( window["Reflect"] === Reflect ); // true

Type of Reflect is object.

〔►see JS: Data Types〕

// type of Reflect
console.log ( typeof Reflect === "object" ); // true
console.log ( Object.prototype.toString.call(Reflect) === "[object Object]" ) // true

The parent of Reflect is Object.prototype. 〔►see JS: Prototype and Inheritance〕〔►see JS: Object.prototype〕

console.log ( Reflect.getPrototypeOf ( Reflect ) === Object.prototype); // true

Purpose of Reflect

The Reflect object is used as namespace to host a group of static functions. (like the Math object. 〔►see JS: Math Object〕 )

Reflect's methods typically:

Provides a function form of operators. For example, Reflect.get ( obj, key ) is the same as obj[key]
Provide a more strict/improved version of existing methods. For example, Reflect.getPrototypeOf(obj) is same as Object.getPrototypeOf(obj), but will throw error if obj is not a object type.

〔►see JS: Object Object〕

〔►see JS: Function Object〕

Properties

Reflect.get ( obj, key , receiver )
Reflect.set ( obj, key, val, receiver )
Reflect.has ( obj, key )

Reflect.defineProperty ( obj, key, attributes )
Reflect.deleteProperty ( obj, key )
Reflect.getOwnPropertyDescriptor ( obj, key )

Reflect.ownKeys ( obj )
~~Reflect.enumerate ( obj )~~

Reflect.getPrototypeOf ( obj )
Reflect.setPrototypeOf ( obj, proto )

Reflect.isExtensible (obj)
Reflect.preventExtensions ( obj )

Reflect.apply ( f, this_binding, argList )
Reflect.construct ( constructor, argList [, newTarget] )

Reference

ECMAScript 2015 §Reflection#sec-reflect-object

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JS: Reflect Object

Purpose of Reflect

Properties

Reflect.get

Reflect.set

Reflect.has

Reflect.defineProperty

Reflect.deleteProperty

Reflect.getOwnPropertyDescriptor

Reflect.ownKeys

Reflect.enumerate

Reflect.getPrototypeOf

Reflect.setPrototypeOf

Reflect.isExtensible

Reflect.preventExtensions

Reflect.apply

Reflect.construct

Reference