ActionScript for Flash MX: The Definitive Guide, Second Edition

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Chapter 3: Data and Datatypes

Programming languages use datatypes to provide rudimentary categories for data.

For example, nearly all programming languages define datatypes to store and manip-

ulate 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 in Chapter 12. 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:

string

For text sequences such as “

hi there”. A string is a series of characters (alphanu-

merics and punctuation).

number

For numbers, such as 351 and 7.5. Numbers are used for counting and for math-

ematical equations.

boolean

For logical decisions. With Boolean data, we can represent or record the status

of some condition or the result of some comparison. Boolean data has only two

legal values:

true and false.

null and undefined

For representing an absence of data, ActionScript provides two ...