JSFiddle - React, Tailwind, and code Playground

JavaScript

var Person = function (optns) {
    if(optns){
        this.name = optns.name || "";
        this.age = parseInt(optns.age) || 0;
    }
}

Person.prototype = {
    getAgePlusTwo: function () {
        return this.age + 2;
    }
}

var json1 = {name: "Person2", age: "22"}
var json2 = {name: "Person3"};

console.log(new Person(json1));
var p2 = new Person(json1);
console.log(p2.getAgePlusTwo())
console.log(new Person());