JSFiddle - React, Tailwind, and code Playground

HTML

<script src="http://cdn.crafty-modules.com/crafty-DEBUG.js"></script>

JavaScript

Crafty.init(100,100);
Crafty.scene("InheritanceExample", function()
{
    Crafty.background("#000");
    function Mammal(name){   //define a javascript class
        this.name=name;  }
    Mammal.prototype.toString = function(){   //define a method of the class
        return "Mammal: "+this.name;  } 
    //Inheritance example 
    Cat.prototype = new Mammal();     //Cat inherits from Mammal class
    Cat.prototype.constructor = Cat;  //otherwise instances of Cat would have a constructor of Mammal
    function Cat(name){
        this.name=name;   }
    Cat.prototype.toString = function(){  
    //Cat's toString method overwrites Mammal's toString method
        return "Cat: "+this.name;  }   
    //We can check by printing the name:
    var myMammal = new Mammal("Mr. Fancypants");
    var myCat = new Cat("Mr. Meow");
    console.log(  myMammal  );
    console.log(  myCat  );
})
Crafty.scene("InheritanceExample");