JSFiddle - React, Tailwind, and code Playground

JavaScript

var Base = function Base() {};

var Derived = function Derived() {};
Derived.prototype = Object.create(Base.prototype);

var obj = new Base();
document.writeln(obj instanceof Base);    // true
document.writeln(obj instanceof Derived); // false

obj.__proto__ = Derived.prototype;
document.writeln(obj instanceof Base);    // true
document.writeln(obj instanceof Derived); // true