JSFiddle - React, Tailwind, and code Playground

by KosteB

HTML

<p>Result:</p>

<div id='results'>
</div>

JavaScript

var Calculator = function(start) {
    var that = this;

    this.add = function(x) {
        start = start + x;
        return that;
    };

    this.multiply = function(x) {
        start = start * x;
        return that;
    };

    this.equals = function(calback) {
        calback(start);
        return that;
    };
};

$(document).ready(function() {

    var resultDiv = document.getElementById('results');
    new Calculator(0)
        .add(1)
        .add(2)
        .multiply(3)
        .equals(function(result) {
            resultDiv.innerHTML = result;
        });
});