JSFiddle - React, Tailwind, and code Playground

HTML

<div id='log'>Log:<br></div>

JavaScript

//Father.js

var Father = function () {
    var init = function () {
        document.getElementById("log").innerHTML += '<br>father w/o ptototype';
    }
};
    
Father.prototype.init = function() {
    document.getElementById("log").innerHTML += '<br>father overloaded by prototype';
 };


//Child.js

var Child = function () {
    }

Child.prototype.init = function(){
    document.getElementById("log").innerHTML += '<br>child';
}

var myfather = new Father();
myfather.init();

var myChild = new Child();
myChild.init();