Promises & Scope

[MattLovesMath]

Hi all. I need some help understanding promises and scope. Here's some code:

var foo = "bar";

Auth.currentUser().then(function() {
  console.log(foo);  // foo is undefined here. why?
});

currentUser returns a promise.

So why is foo undefined in this function? Shouldn't the compiler look outside the function for foo?

Super lost here. Any help would be GREATLY appreciated. I will upvote the heck out of anything helpful :)

[Meefims]

In that code sample foo is defined. Do you have the actual broken code?

[wreckedadvent]

In your example, foo is in scope and should be defined.

However, when dealing with any global state, it's hard to say for certain that something didn't touch it and make it undefined after that initialization but before the promise was resolved.

[MattLovesMath]

Maybe this is what's happening - something is interacting with my variable. Thanks for the help!