JSFiddle - React, Tailwind, and code Playground

JavaScript

function class1(param) {
    this.param = param;
}

class1.prototype.method1 = function () {
    console.log(this.param);
}

$('document').ready(function () {
   var object1 = new class1('foo');
   var object2 = new class1('bar');
   object1.method1(); // expected: foo , actual: foo 
});