Main.js

var person = require("./Person")
var p = new person.Person('John');
p.show();
console.log("direct access: " + p.name);

Main.ts

import person = module("Person");

var p:person.Person = new person.Person('John');
p.show();

console.log("direct access: " + p.name);

Main_modify.js

var person = require("./Person_modify")
var p = new person.Person('John');
p.show();
console.log("direct access: " + p.name);

output.txt

$ node Main.js
John
direct access: John

$ node Main_modify.js
John
direct access: undefined

Person.js

var Person = (function () {
    function Person(n) {
        this.name = n;
    }
    Person.prototype.show = function () {
        console.log(this.name);
    };
    return Person;
})();
exports.Person = Person;

Person.ts

export class Person {
    private name:string;
    constructor (n:string){
        this.name = n;
    }
    show(){
        console.log(this.name);
    }
}

Person_modify.js

var Person = (function () {
    var name;
    function Person(n) {
        name = n;
    }
    Person.prototype.show = function () {
        console.log(name);
    };
    return Person;
})();
exports.Person = Person;