Learn ECMAScript - Second Edition

The getPrototypeOf(target) method

The getPrototypeOf trap is executed when we retrieve the value of the internal [[prototype]] property, using either the Object.getPrototypeOf() method or the __proto__ property. It takes only one parameter--that is, the target object.

It must return an object or null value. The null value indicates that the object doesn't inherit anything else and is the end of the inheritance chain.

Here is a code example that demonstrates how to use the getPrototypeOf trap:

const proxy = new Proxy({    age: 12,     __proto__: {name: "Eden"}}, {     getPrototypeOf(target) {         return Object.getPrototypeOf(target);     } }); console.log(Reflect.getPrototypeOf(proxy).name); //Output "Eden"