Calling a variable inside of a function like a global variable but without polluting the global scope.

variableBinding.js

// Calling a variable inside of a function
// like a global variable but without polluting the global scope.
// main function
function setup() {
  console.log(ADD);
  console.log(SUB);
  console.log(sum(100,50))
}

// init the variables in another function (you can hide the function in an external js file)
function _setup() {
  this.ADD = 'ADD';
  this.SUB = 'SUB';
  this.sum = function (s1, s2) {
    return s1 + s2;
  }
}

// does not work with prototypes
// setup.prototype.sub = function(a1,a2) {
// 	return a1-a2;
// }

// bind the Scope of setup with _setup;
setup = setup.bind(_setup(), null);
setup(); //finnaly all the setup()