differences of function declarations?

Hey Johnny:

The difference between a function declaration(function addTask () {}) and a function expression (var addTask = function () {}) has to do with the way JavaScript code is executed.

A function declaration can be used before it is declared (this is through a process called function hoisting):

foo(); // "Hello, my name is Andrew"
function foo () {
  console.log("Hello, my name is Andrew");
}

With a function expression, the expression must be declared before it is used, otherwise your program will throw an error:

foo(); // ReferenceError: foo is not defined
var foo = function () {
  console.log("Hello, my name is Andrew");
};

Aside from that, the functions themselves work the same way.

Hope that helps!

-Andrew

I understand the differences between the two types of function assignments and how they both use hoisting in different ways. What I'm not clear on is why the instructor used function expressions instead of function declarations with this course. As Johnny Lopez mentions above, at one point Andrew specifies that he will explain later why he chose to use function expressions. I don't recall it ever being elaborated on after that.

Can anyone else weigh in on this?

You can assign them both. They mean the same thing.

Most languages have anonymous function which is what these are.

var Cb = function () {};

el.onclick = Cb;

And your alternative way works too.

function Cb () {};

el.onclick = Cb;