JSFiddle - React, Tailwind, and code Playground

JavaScript

function myObject() {
    
    var that = this;

    this.variable1 = "tst";

    this.function1 = function() {
        //Now this function works.  A 'this' function to a private function is ok
        _PrivateFunction1();

        //Here is error one, I cannot seem to call methods within the object
        //from.  
        this.function2();
    }

    this.function2 = function() {
        alert("look! function2!");
    }

    function _PrivateFunction1() {
        //This does work though.  I am confused.
        _PrivateFunction2();
    }

    var _PrivateFunction2 = function() {
        alert("look! PrivateFunction1");

        //this does not work.
        alert(that.variable1);
        alert('this === window ' + (this === window));
    }
}

obj = new myObject();
obj.function1();