Reflect
Reflect 是一個內建物件,提供了用於獲取可截取之 JavaScript 操作的方法。這些方法與 proxy handlers (en-US) 的方法相同。Reflect
不是一個函式物件,因此它是不可建構的。
描述
Unlike most global objects, Reflect
is not a constructor. You can not 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
object).
方法
The Reflect
object provides the following static functions which have the same names as the proxy handler methods (en-US). Some of these methods are the same as corresponding methods on Object
.
Reflect.apply()
(en-US)-
Calls a target function with arguments as specified by the
args
parameter. See alsoFunction.prototype.apply()
. Reflect.construct()
(en-US)-
The
new
operator as a function. Equivalent to callingnew target(...args)
. Reflect.defineProperty()
(en-US)-
Similar to
Object.defineProperty()
. Returns aBoolean
. Reflect.deleteProperty()
(en-US)-
The
delete
operator as a function. Equivalent to callingdelete target[name]
. Reflect.get()
(en-US)-
A function that returns the value of properties.
Reflect.getOwnPropertyDescriptor()
(en-US)-
Similar to
Object.getOwnPropertyDescriptor()
(en-US). Returns a property descriptor of the given property if it exists on the object,undefined
otherwise. Reflect.getPrototypeOf()
(en-US)-
Same as
Object.getPrototypeOf()
. Reflect.has()
(en-US)-
The
in
operator (en-US) as function. Returns a boolean indicating whether an own or inherited property exists. Reflect.isExtensible()
(en-US)-
Same as
Object.isExtensible()
(en-US). Reflect.ownKeys()
(en-US)-
Returns an array of the target object's own (not inherited) property keys.
Reflect.preventExtensions()
(en-US)-
Similar to
Object.preventExtensions()
. Returns aBoolean
. Reflect.set()
(en-US)-
A function that assigns values to properties. Returns a
Boolean
that istrue
if the update was successful. Reflect.setPrototypeOf()
(en-US)-
A function that sets the prototype of an object.
規範
Specification |
---|
ECMAScript Language Specification # sec-reflect-object |
瀏覽器相容性
BCD tables only load in the browser
參見
- The
Proxy
global object. - The
handler
(en-US) object.