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.

Recursive Functions

|

203

Note that new values assigned to individual elements of the array from inside a func-

tion are reflected outside the function as well. However, suppose that instead of

assigning new values to one or more elements, we assign a new value to the parame-

ter itself. Doing so will break its association with the original argument. Subsequent

changes to the parameter variable will have no effect on the original argument, as

shown in Example 9-7. In this example, although the

boys array is passed as an argu-

ment, the myArray parameter variable is immediately set to girls. Subsequent

changes to

myArray affect the girls array, not the boys array.

More information on primitive and composite data can be found in Chapter 3.

Recursive Functions

A recursive function is a function that calls itself (by using its own name within its

function body). Here’s a simple example that shows the principle of recursion. But

because the code tells the trouble() function to execute repeatedly (like an image

reflected infinitely in two opposing mirrors), Flash will quickly exceed its maximum

recursion limits, causing an error:

function trouble () {

trouble();

}

// Pass our array to the function

setValue(boys);

// Check the value of our array elements

trace("Boys: " + boys); // Displays: "Boys: Sid,Graham,Derek" ...