ActionScript for Flash MX: The Definitive Guide, Second Edition

This is the Title of the Book, eMatter Edition

Copyright © 2007 O’Reilly & Associates, Inc. All rights reserved.

Stopping a Loop Prematurely

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173

The break Statement

The break statement ends execution of the current loop or switch statement (as we

saw in Chapter 7). It has the modest syntax:

break

The only requirement is that break must appear within the body of a loop or switch

statement.

The break statement provides a way to halt a process that is no longer worth com-

pleting. For example, we can use a for-in loop to build a form-checking routine that

cycles through the input-text variables on a timeline. If a blank input field is found,

we alert the user that she hasn’t filled in the form properly. We can abort the pro-

cess by executing a break statement. Example 8-3 shows the code. Note that the

example assumes the existence of a movie clip called

form_mc that contains a series of

declared input variables named

input01_txt, input02_txt, and so on.

The continue Statement

The continue statement is similar to the break statement in that it causes the current

iteration of a loop to be aborted; but, unlike break, it resumes the loop’s execution

with the next natural cycle. The syntax of the continue statement is simply:

continue

In all types of loops, the continue statement interrupts the current iteration of the

loop body, but the resumption of the loop varies slightly depending on the type of

loop