Comparing two variables with if statements

Question

I'm working with 2 global variables and I need to compare them on 6 different button function clicks for a lot of different scenarios.
Here is an example of what I have for 1 button:
my Btn.onPress = function() {
_global.firstVar = 19;
_global.firstYear =2009;
_root.checkAll();
My function is starting to look like this;
if ((_global.firstVar == 19) && (_global.firstYear == 2009)){     (first...is this the correct way to write this statement with the && to compare?)
  gotoAndStop(8);
  trace("itworks")
  loadMovie("mymovie.swf", 1);
else if..........
only problem i see is that there are many different scenarios and this if statement could get very long.
Is there a way to combine it somehow so there wouldn't be that many else if's?

Answer 1

That is most likely the way to write it, but I have the feeling that you are making it much more complex than it needs to be. What are you actually trying to do?
How are firstVar and firstYear being set? Can they be any number at all or just some specific ones?
Using _global variables isn't really a best practice and should only be done the most unusual of circumstances. There are some tricky things about the _global object. Generally they are just a shortcut for getting around scope problems, but if you have those problems it is better to work them out and understand scope that to just put everything in _global. In AS3, the _global object has gone away—unless you make your own....
Also depending upon what you are doing with the loading of the swf, you probably should look into using the MovieClipLoader instead of a loadMovie. With loadMovie there is no easy way to know when the clip has finished loading, unless you write your own preloader code. With the MovieClipLoader class there is a nice simple event called onInit. You can also use the onLoadProgress event to know how much of your external asset has loaded.
Also using gotoAndStop(8) or some other number is likely to become confusing later down the line. You might want to use labels and names. If you have a lot of different scenarios then maybe give them names. That way if the timeline changes or you come back in 3 months it will generally be easier to track down:
gotoAndStop('midYearReviewScenario")
rather than
gotoAndStop(14);
Just a suggestion from years' of experiences.
And finally I'm with Ned. Generally for buttons onRelease is a better event to do navigation and other results things that happen upon a click. onPress is really for things where you need to press and hold the button.