JSFiddle - React, Tailwind, and code Playground

JavaScript

function Person(){
    if(arguments[0]) for(var prop in arguments[0]) this[prop] = arguments[0][prop];
}
var gino = new Person({lastName:'Pietermaai',firstName:'Gino'});
console.log(gino);
Person.prototype.getFullName = function(){
    return this.lastName + ' ' + this.firstName;
}
console.log(gino.getFullName());