Object.getPrototypeOf()

gistfile1.js

// Object.getPrototypeOf(obj);
var obj = Object.create({}); // creates an empty object and is equivalent to obj = {} or obj = Object.create(Object.prototype)
var obj1 = {
    foo : 1,
    bar : function() {
        return 'Bar method called';
    }
};

var obj3 = Object.create(obj1, {
    baz : {
        value : 'Hello World'
    }
});

Object.getPrototypeOf( obj3 ) === obj1; // returns true