JavaScript handler.getPrototypeOf() Method

The handler.getPrototypeOf() method is a trap for the internal method. If target is not extensible, then this method returns the same value as Object.getPrototypeOf(target).

Syntax

Parameters

target: The target object.

Return value

This method returns an object or null.

Browser Support

Chrome	NO
Edge	NO
Firefox	49
Opera	NO

Example 1

const obj = {};
const proto = {};
const hag = {
    getPrototypeOf(target) {
        document.writeln (target === obj);  
        document.writeln (this === hag); 
        return proto;
    }
};
const p = new Proxy(obj, hag);
document.writeln(Object.getPrototypeOf(p) === proto); 

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Output:

true true true

Example 2

var obj = {};
var p = new Proxy(obj, {
    getPrototypeOf(target) {
        return Array.prototype;
    }
});
document.write(
  
    p instanceof Array  
);

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Output:

true

Example 3

const Prototype = {
  eyeCount : 32
};
const handler = {
  getPrototypeOf(target) {
    return Prototype;
  }
};
const obj = new Proxy(Prototype, handler);
document.writeln(Object.getPrototypeOf(obj) == Prototype);

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Output: