AppleScript in a Nutshell

Chapter 3. Data Types

In Chapter 1, I touched on data types, but now I will delve deeper! A data type describes how a programming system stores data in memory, and it is similar to the types used by other languages such as Java or Visual Basic. AppleScript data types specify the type of value that a variable stores (e.g., date, integer, string, real) or that an AppleScript command or scripting addition returns (see Appendix A). The data type that a variable stores determines what the script can do with it afterward, such as perform a math operation on an integer type or find out the length property (the number of characters) of a string type.

This chapter only describes the built-in AppleScript data types; however, a variable could also store a reference to an object such as a file, a web URL, or a database record (see Chapter 1 and its discussion of Apple event objects). Table 3-1 lists the data types described in this chapter, which also includes the correct syntax to use when storing a certain data type in a variable and the other data types to which a variable can allowably be cast or coerced.

Table 3-1. AppleScript Data Types

alias	real
boolean	record
class	reference
constant	RGB color
data	string
date	styled Clipboard Text
file specification	styled Text
integer	text
international Text	Unicode text
list	unit of measurement classes
number

With some exceptions such as the date data type, you do not have to declare a data type when you declare a variable. ...