Fraser Crosbie – Calgary Flash & Flex Developer

When learning any new programming language the first exercise is always…
you guessed it! Hello World!.

Open a text editor, I use SEPY for coding ActionScript, and type the following code:

package ca.flashdev.hello {
  public class HelloWorld {
    public function sayHello():String {
      var greeting:String = "Hello World!";
      return greeting;
    }
  }
}

Save this file as HelloWorld.as. Place it in a folder structure ca\flashdev\hello\.
If you already code in ActionScript 2 you will notice the addition of package to the top of my code. When you use OOP you place your class files in a folder structures. Each folder is considered a package. When you import classes into your code you have to option of importing an entire folder of classes using the * symbol (e.g. import ca.flashdev.utils.*). Packages let us organize classes into logical groups and also prevent naming conflicts between classes. Now in ActionScript 3 you put the package name (the folder name that this class file is contained inside) in the top of you class file.

The next step is to open Adobe Flash 9 Public Alpha. File -> New -> Flash Document. Select the Text Tool (t) and create a dynamic text field on the stage with an instance name of hello_txt. Click Embed in the properties panel and select Uppercase, Lowercase and Punctuation. Create another Layer in the Timeline and name it actions. Click on the new blank frame in the Timeline, open your Actions (F9) panel and add the following code:

import ca.flashdev.hello.HelloWorld;
var classInstance:HelloWorld = new HelloWorld();

hello_txt.text = classInstance.sayHello();

Save this file in the same folder as your ca folder and name it helloWorld.fla. Now publish the Movie (Ctrl-Enter). The text field you added should display Hello World!.

Make sure you have ActionScript 3 selected in the ActionScript Version field of your Publish Settings (Ctrl-Shift-F12).

Download the Source Files