JSFiddle - React, Tailwind, and code Playground

JavaScript

var UserDTO = (function () {
    function UserDTO() {
    }
    UserDTO.prototype.getFUllName = function () {
        return this.FirstName + ' ' + this.LastName;
    };
    return UserDTO;
})();

var o = new UserDTO();
o.FirstName = 'John';
o.LastName = 'Doe';
console.log(o.getFUllName());