ActionScript: The Definitive Guide

Retaining Meaning with Datatypes

How do we store information as raw data in a computer without losing meaning? By categorizing our data and defining its datatype, we give it context that defines its meaning.

For example, suppose we have three numbers: 5155534, 5159592, and 4593030. By categorizing our data—as, say, a phone number, fax number, and parcel tracking number—the context (and, hence, the meaning) of our data is preserved. When categorized, each of the otherwise-nondescript seven-digit numbers becomes meaningful.

Programming languages use datatypes to provide rudimentary categories for our data. For example, nearly all programming languages define datatypes to store and manipulate text (a.k.a. strings) and numbers. To distinguish between multiple numbers, we can use well-conceived variable names, such as phoneNumber and faxNumber. In more complex situations, we can create our own custom data categories with objects and object classes as covered later. Before we think about making our own data categories, let’s see which categories come built into ActionScript.

The ActionScript Datatypes

When programming, we may want to store a product name, a background color, or the number of stars to be placed in a night sky. We use the following ActionScript datatypes to store our data:

• For text sequences like "hi there," ActionScript provides the string datatype. A string is a series of characters (alphanumerics and punctuation).

• For numbers, such as 351 and 7.5, ActionScript provides the ...