JSFiddle - React, Tailwind, and code Playground

JavaScript

function clone(obj) {

    if (null == obj || "object" != typeof obj)
        return obj;
    var copy = obj.constructor();
    for (var attr in obj) {
        if (obj.hasOwnProperty(attr))
            copy[attr] = obj[attr];
    }
    return copy;
}

var User = {
    _firstName: 'robert',
    
    get firstName() {
        return this._firstName;
    },
    set firstName(val) {
        this._firstName = val;
    },
    
    affFirstName: function() {
        console.log(this._firstName);
    },
};
    
console.log(User);
var User2 = clone(User);    
console.log(User2);