I am working with ES6 Proxy. I have created a proxy of an array, now when i check the type of proxy it is giving me as Object type.
Question:
How can i check if the proxy i have created was for array or object?
Example:
const arr = ['a', 'b', 'c'];
const arrProxy = new Proxy(arr, {});
alert(typeof(arrProxy));UPDATE (SOLUTION):
Instead of using typeof, we should use Array.isArray
const arr = ['a', 'b', 'c'];
const arrProxy = new Proxy(arr, {});
alert(Array.isArray(arrProxy));
You can't tell that a proxy is a proxy. That's part of the point of them, they provide a facade (one you can't detect) around another object.
As far as code looking at your arrProxy can tell, it's an array:
const arr = ['a', 'b', 'c'];
const arrProxy = new Proxy(arr, {});
console.log(Array.isArray(arrProxy)); // trueSeparately: typeof is very general, it gives you "object" for a huge range of things: Anything that's of an object (not primitive) type (including null). So typeof new Map(), typeof new Set(), typeof null, typeof document (on browsers), etc., will all give you "object". (Also note that typeof is an operator, not a function; no need for the () in your code sample.)
As other answers suggest, you cannot tell if something is a proxy.
So you might need to implement it yourself.
Here is an example from: https://exploringjs.com/deep-js/ch_proxies.html#transparent-virtualization-and-handler-encapsulation
const proxies = new WeakSet();
export function createProxy(obj) {
const handler = {};
const proxy = new Proxy(obj, handler);
proxies.add(proxy);
return proxy;
}
export function isProxy(obj) {
return proxies.has(obj);
}
There is also one way to do this using instanceof:
if (arrProxy instanceof Array) {
console.log('This is an array!');
}
Array.isArray.
another realm here?instanceof won't work. Similarly if one window opens another, if you pass data between them, that data is crossing realms.instanceof. When i am using arrProxy instanceof Object it still gives me true.
__proto__ of Array is Object that is why arrProxy instanceof Object is also true
typeof []is also 'object', tryArray.isArray(arrProxy)arrProxyis an array, or how to tell it's a proxy?