JSFiddle - React, Tailwind, and code Playground

HTML

<div id="dog1" class="dog">click me</div>

CSS

.dog {
    background:#ccc;
    color:#666;
    border:1px solid #333;
    width:100px;
    height:100px;
    text-align:center;
}

JavaScript

function Dog(name, id) {
    this.name = name ? name : "spot";
    this.id = id ? id : "dog";
    this.el = document.getElementById(this.id);
    this.el.addEventListener("click", this, false);
}
Dog.prototype = {
    handleEvent: function (event) {
        switch (event.type) {
            case "click":
                return this.speak();
        }
    },
    speak: function () {
    alert('TEST' + " " + this.name + " " + myDog.name)
        console.log("this.name: " + this.name + "\nmyDog.name: " + myDog.name);
    }
};

var myDog = new Dog("tye33", "dog1");