Why does IIFE function return undefined when value is passed instead of an Object?

Question

I'm learning Javascript at the moment, Please look at this snippet of code:

I've here defined 3 Immediately Invoked Function Expressions. My expectation here is when I console.log(controller) it returns undefined . Can anyone please explain me, why does controller IIFE be able to return an Object but not a value?

 var budgetController = (function() { var x = 23; var add = function(a) { return x + a; } return { publicTest: function(b) { console.log(add(b)); } } })(); var UIController = (function() { //Some UI based Code })(); var controller = (function(budgetCtrl, UICtrl) { var z = budgetCtrl.publicTest(5); return z; })(budgetController, UIController); console.log(controller); // Should return the value of 'z' [My Confusion/Misconception lies here] console.log(budgetController); // Returns a Object 

Answer 1

since you are passing params to publicTest, you should return the value to store it in Z variable

 var budgetController = (function() { var x = 23; var add = function(a) { return x + a; }; return { publicTest: function(b) { console.log(add(b)); return add(b); } }; })(); var UIController = (function() { //Some UI based Code })(); var controller = (function(budgetCtrl, UICtrl) { var z = budgetCtrl.publicTest(5); return z; })(budgetController, UIController); console.log(controller); // Should return the value of 'z' [My Confusion/Misconception lies here] console.log(budgetController);