Object.getPrototypeOf() - JavaScript | MDN

Try it

const prototype = {};
const object = Object.create(prototype);

console.log(Object.getPrototypeOf(object) === prototype);
// Expected output: true

Syntax

js

Object.getPrototypeOf(obj)

Parameters

obj

The object whose prototype is to be returned.

Return value

The prototype of the given object, which may be null.

Examples

Using getPrototypeOf

js

const proto = {};
const obj = Object.create(proto);
Object.getPrototypeOf(obj) === proto; // true

Non-object coercion

In ES5, it will throw a TypeError exception if the obj parameter isn't an object. In ES2015, the parameter will be coerced to an Object.

js

Object.getPrototypeOf("foo");
// TypeError: "foo" is not an object (ES5 code)
Object.getPrototypeOf("foo");
// String.prototype                  (ES2015 code)

Specifications

Specification
ECMAScript® 2027 Language Specification
# sec-object.getprototypeof

Browser compatibility

See also

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