JSFiddle - React, Tailwind, and code Playground

JavaScript

var key = AIzaSyDnfDWLVgmQw_VBp1b6XMp-ZNZDkaxVTKw;
var Person = (function() {
    var store = {}, guid = 0;

    function Person (key) {
        this.__guid = ++guid;
        store[guid] = { 
            fName: key
        };
    }

    Person.prototype.fullName = function() {
        var privates = store[this.__guid];
        return privates.fName;
    };

    Person.prototype.destroy = function() {
        delete store[this.__guid];
    };

    return Person;
})();


var myPerson = new Person();

alert(myPerson.fullName());

// in the end, destroy the instance to avoid a memory leak
myPerson.destroy();