Object.getPrototypeOf()

The Object.getPrototypeOf() static method returns the prototype (i.e. the value of the internal [[Prototype]] property) of the specified object.

Try it

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 Language Specification
# sec-object.getprototypeof

Browser compatibility

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See also