Common Actionscript Errors and Debugging

Common errors and debugging

When you become an accomplished programmer, you actually get worried when your code works for the first time; surely this is wrong, it works! Yes, such is the tragedy of computer work; it never quite works as intended. Actionscript is no different. Sooner or later you will stumble into a bug that will seem impossible to iron out.

Looking at the boards and at feedback from previous tutorials, I've spotted what I believe to be the most common Actionscript errors. These vary from basic to advanced; even expert coders may learn a thing or two. Before looking at these errors, I present a brief review of Flash's debugging tools.

Debugging Actionscript

1. The trace action

The most primitive of the Flash debugging tools, it's been around since Flash 4. It will send a string to the output window when you test your movie inside the Flash IDE. It can be used to see if a function is called, if a movieclip is correctly targeted, if a variable has the right value and so forth. Even though it is primitive, I still use it all the time, and you should too. Use like this:

trace("I'm a trace action!");

Or with a variable:

myTrace = "I'm the content of a variable";
trace(myTrace);