JS ReferencesLesson #259
Reflect & Proxy Reference
> Reflect is safe and flexible, especially when used inside a Proxy.
Complete Reflect Reference
Revised December 2025
| Method | Description |
|---|---|
| Reflect.apply() | Call a function |
| Reflect.construct() | Create object (like new) |
| Reflect.defineProperty() | Define a property |
| Reflect.deleteProperty() | Delete a property |
| Reflect.get() | Get a property |
| Reflect.getOwnPropertyDescriptor() | Get property descriptor |
| Reflect.getPrototypeOf() | Get the prototype of an object |
| Reflect.has() | Check if property exists |
| Reflect.isExtensible() | Check if object can grow |
| Reflect.ownKeys() | Get all keys (incl. symbols) |
| Reflect.preventExtensions() | Stop object from growing |
| Reflect.set() | Set a property |
| Reflect.setPrototypeOf() | Set the prototype of an object |
Why Reflect
> Reflect is safe and flexible, especially when used inside a Proxy.
Complete Proxy Handler Reference
Revised December 2025
| Method | Description |
|---|---|
| handler.apply() | Call a function |
| handler.construct() | Create object (like new) |
| handler.defineProperty() | Define a property |
| handler.deleteProperty() | Delete a property |
| handler.get() | Get a property |
| handler.getOwnPropertyDescriptor() | Get property descriptor |
| handler.getPrototypeOf() | Get the prototype of an object |
| handler.has() | Check if property exists |
| handler.isExtensible() | Check if object can grow |
| handler.ownKeys() | Get all keys (incl. symbols) |
| handler.preventExtensions() | Stop object from growing |
| handler.set() | Set a property |
| handler.setPrototypeOf() | Set the prototype of an object |
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JavaScript Internal Methods
All JavaScript objects have 13 internal methods.
Each method has a corresponding Proxy trap:
| Internal Operation | Proxy trap |
|---|---|
| [[Construct]] | construct() |
| [[Call]] | apply() |
| [[Get]] | get() |
| [[Set]] | set() |
| [[HasProperty]] | has() |
| [[Delete]] | deleteProperty() |
| [[DefineProperty]] | defineProperty() |
| [[GetOwnProperty]] | getOwnProperty() |
| [[OwnPropertyKeys]] | ownPropertyKeys() |
| [[IsExstensible]] | isExtensible() |
| [[PreventExstensions]] | preventExtensions() |
| [[GetPrototypeOf]] | getPrototypeOf() |
| [[SetPrototypeOf]] | setPrototypeOf() |
Every Proxy trap has a Reflect method with the same name and signature.
| Internal Operation | Reflect Method |
|---|---|
| [[Construct]] | Reflect.construct() |
| [[Call]] | Reflect.apply() |
| [[Get]] | Reflect.get() |
| [[Set]] | Reflect.set() |
| [[HasProperty]] | Reflect.has() |
| [[Delete]] | Reflect.deleteProperty() |
| [[DefineProperty]] | Reflect.defineProperty() |
| [[GetOwnProperty]] | Reflect.getOwnProperty() |
| [[OwnPropertyKeys]] | Reflect.ownPropertyKeys() |
| [[IsExstensible]] | Reflect.isExtensible() |
| [[PreventExstensions]] | Reflect.preventExtensions() |
| [[GetPrototypeOf]] | Reflect.getPrototypeOf() |
| [[SetPrototypeOf]] | Reflect.setPrototypeOf() |
Learn More
> JavaScript Metaprogramming
> JavaScript Reflect Tutorial
> JavaScript Proxy Tutorial