JSFiddle - React, Tailwind, and code Playground

JavaScript

var MyObj = function(name) {
  this.name = name;
};

MyObj.prototype = {
  called_often: function() {
    // lots more code than just the following
    return 'VALUE'; //document.getElementById('someID').value;
  },

  global_default: 'value', // can be changed, so need to pull value when run

  does_stuff: function(value) {
    var str = this.global_default + value, // can't access global_default on its own
        input = this.called_often(), // doesn't work; MyObj.prototype.called_often() DOES
        name = this.name; // 'this' used in the prototype doesn't work
                          // even within a created object
    return name + input + str;
  }
};

var obj = new MyObj('Bob');
alert(obj.does_stuff('a'));