JSFiddle - React, Tailwind, and code Playground

JavaScript

function First(name){
       this.name=name;
   }
   First.prototype.hair='black';// tom.hair gets me undefined
   function Second(){
       this.age=1;
   }

   First.prototype.age=new Second().age;
   var tom=new First('tom');
   tom.nail='sharp';// added property to tom
   for(var i in tom){
       console.log(i);
   }
   console.log(tom.age);