Adobe Flash

Objects and Classes in Flash

Classes are the blueprint for objects in Macromedia Flash Basic 8 and Macromedia Flash Professional 8. All objects in Flash have an underlying class; for example, all movie clips have a method called getURL(), and getURL() is defined in the class definition for a movie clip. Flash contains many predefined classes, such as the MovieClip class, the Array class, the Color class, and the CheckBox class. This tutorial will show you how to create and modify classes.

First, you'll view the finished files and set up your workspace to use an optimal layout for taking lessons.

  1. View the finished files. This lesson does not include start files. You can find finished files of handson1.fla, handson2.fla, handson3.fla, Product.as, and Drag.as, which are examples of the files that you'll create in this lesson:
    • In Windows, browse to boot drive \Program Files\ Macromedia\ Flash 8\Samples and Tutorials\ Tutorial Assets\ActionScript\ Work with Objects and Classes.
    • On the Macintosh, browse to Macintosh HD /Applications/ Macromedia Flash 8/Samples and Tutorials/Tutorial Assets/ ActionScript/Work with Objects and Classes.
  2. Select Window > Workspace Layout > Default to configure your workspace.

Learn about classes and object types

A class, also referred to as an object type, is like a blueprint. An object doesn't exist until you create it, or instantiate it, from a class definition. An object is an instance of a class.

Properties are the characteristics of an object. For example, when you align movie clips, you change the _x and _y properties of the MovieClip object. A property is a variable that is attached to a class. A property can either be public, which means it is accessible outside the class, or private, which means it can be accessed only within the class.

In object-oriented terms, a method is a behavior or procedure that can act on the object. A hypothetical throw() method on a ball would know the size and weight of the ball. A method is aware of the object and all the properties that it contains and can work on that object.

by BrainBellupdated
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