Control Statements

A control statement is statement that controls when and how other statements are executed. Most control statements are compound statements--that is, statements that contain other statements.

By default, AppleScript executes the statements in a script in sequence, one after the other. Control statements can change the order in which AppleScript executes statements by causing AppleScript to repeat or skip statements or go to a different statement.

The first two sections in this chapter provide general information on working with control statements:

Characteristics of Control Statements, provides an overview of control statements.
Debugging Control Statements describes how to use the Event Log window to help debug control statements.

The rest of the chapter describes the following AppleScript control statements:

Tell Statements define the default target to which commands are sent if no direct object is specified.
If Statements allow you to execute or skip statements based on the outcome of one or more tests.
Repeat Statements allow you to repeat a series of statements.
Try Statements allow you to handle error messages.
Considering and Ignoring Statements allow you to consider or ignore certain attributes, such as case, punctuation, and white space, in string comparisons.
With Timeout Statements allow you to specify how long AppleScript waits for an application command or scripting addition to complete before stopping execution of the script and returning an error.
With Transaction Statements allow you to take advantage of applications that support the notion of a transaction--a sequence of related events that should be performed as if they were a single operation.

Table A-4 summarizes the syntax for the control statements that are described in this chapter.