JSFiddle - React, Tailwind, and code Playground

JavaScript

var myConstructor = function(){
  var bar = function() {;
    obj.value = 2; 
  };
  
  var obj = {
      foo: function(){
          bar();
      },
    value: 1
  };
    
    return obj;
};

var obj = new myConstructor();
alert(obj.value); // value = 1
obj.foo();
alert(obj.value);