The Object.getPrototypeOf() static method returns the prototype
(i.e. the value of the internal <span class="createlink">Prototype</span> property) of the specified
object.
Syntax
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
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.
Object.getPrototypeOf("foo");
// TypeError: "foo" is not an object (ES5 code)
Object.getPrototypeOf("foo");
// String.prototype (ES2015 code)