ActionScript for Flash MX: The Definitive Guide, Second Edition

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

Removing Elements from an Array

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Removing Elements from an Array

You can remove elements from an array by using the delete operator, reducing the

length property of an array, or using one of the built-in array methods.

Removing Numbered Elements with the delete Operator

The delete operator sets an array element to undefined, using the following syntax:

delete arrayName[index]

where arrayName is any array and index is the number or name of the element we

want to set to undefined. When used with numbered (not named) elements, the

name delete is misleading, frankly. It does not remove a numbered element from the

array; it merely sets the target element’s value to

undefined.Adelete operation, there-

fore, is identical to assigning the

undefined value to an element. We can verify this by

checking the

length property of an array after deleting one of its elements:

var myList = ["a", "b", "c"];

trace(myList.length); // Displays: 3

delete myList[2];

trace(myList.length); // Still displays 3...the element at index 2 is

// undefined instead of "c", but it still exists

To truly delete elements, use splice() (to delete them from the middle of an array), or

use shift() and pop() (to delete them from the beginning or end of an array). Note

that delete behaves differently with named elements than with ...