Button.onPress/on(press)?

Today, I'd like to answer a reader's email. Maybe it's something you've wondered about for a while.

Here's the question:

I would like to ask if what is the difference between the two sample script below. Because when I try it, they work exactly the same. Which script is better to used and why? Why is Sample 1 is written in that way, is there an advantage of using it instead if the other?

I put this script on frame 1 of my movie.
Sample 1:

myButton.onPress = function(){
gotoAndPlay(_currentframe + 1);
}


I put this script on the myButton.
Sample 2:

on(press){
gotoAndPlay(_currentframe + 1);
}

Thank you.

Here is my response:

There is no real difference in the end result that is achieved. There is a benefit to using the first sample script, however. Here's how.

If you have 5 buttons on the stage, and 4 movie clip instances, placing scripts on each one individually can become a workflow nightmare. You probably know the kind, 'which button/movie clip instance is doing what, I've got to click on each one to find out.' The syntax as shown in your Sample 1 can help eliminate this problem because it allows you to script the functionality of all the current elements on the stage, from a single script that exists on a frame on the timeline. In other words, instead of having scripts in 9 locations (confusing), they would all exist in a single location, a frame on the timeline - easier to edit and debug.

On a side note, placing scripts on the timeline in this manner is recommended by Macromedia. It's a smarter way to code.

More information can be found about using the syntax shown in Sample 1 on pages 75-82 of my book, Macromedia Flash ActionScripting: Advanced Training from the Source, or pages 487-499 of my other book, Macromedia Flash MX Creative Web Animation and Interactivity.