📘Reflect
Last updated
Last updated
JS ⟩ object ⟩ built-in ⟩ Reflect
A built-in object that provides methods for interceptable operations. The methods are the same as those of proxy handlers.
Reflect is not a function object, so it's not constructible
the first parameter to all the Reflect methods is called the target parameter.
| Reflect.method() | Triggers when… |
|---|---|
apply(f, o, args)
invokes f as a method of o , just like o.f(args).
same as f.apply(o, args).
construct(C, args, newTarget)
invokes C as a constructor.
same as new C(...args).
newTarget is used as new.target (if specified).
defineProperty(o, key, desc)
define new/existing property.
similar to Object.defineProperty(o, key, desc).
but returns boolean.
deleteProperty(o, key)
delete a property.
similar to delete o[key].
returns boolean.
get(o, key, receiver)
get a property.
similar to o[key].
(not sure what the receiver is for. )
getOwnPropertyDescriptor(o, key)
get a property descriptor.
(almost) same as Object.getOwnPropertyDescriptor(o, key)
get the prototype of an object.
(almost) same as Object.getPrototypeOf(o).
has(o, key)
check if object o has property key.
similar to key in o.
returns true for any inherited properties.
isExtensible(o)
check if an object is extensible.
(almost) same as Object.isExtensible(o)
ownKeys(o)
returns an array of own property keys. (string/symbol included)
similar to Object.getOwnPropertyNames(o) + Object.getOwnPropertySymbols(o).
prevents new properties from being added to an object.
(almost) same as Object.preventExtensions(o)
set(o, key, value, receiver)
set a property.
similar to o[key] = value.
returns boolean.
(not sure what the receiver is for )
setPrototypeOf(o, p)
set the prototype of an object. (not recommended)
similar to Object.setPrototypeOf(o, p).
returns boolean.