JSFiddle - React, Tailwind, and code Playground

JavaScript

// Base constructor, like a baseclass in Java
function Base() {
    this.baseProperty = "baseValue";
}
// Base implementation of a method
Base.prototype.printSelf = function () {
    console.log(this.baseProperty);
};

// Constructor, corresponding to a subclass in Java
function Obj() {
    // Call "baseclass" constructor
    Base.call(this);
    this.property = "someValue";
}
// Inherit prototype from Base
Obj.prototype = Object.create(Base.prototype);
// Overload printSelf
Obj.prototype.printSelf = function () {
    // Call base implementation
    Base.prototype.printSelf.call(this);
    console.log(this.property);
};

var obj = new Obj();
obj.printSelf();