Named Array Elements (ActionScript: The Definitive Guide)

11.6.1. Creating and Referencing Named Array Elements

To add an element that can later be retrieved by name, we use the familiar square brackets, with a string instead of a number, on an existing array:

arrayName[elementName] = expression

where elementName is a string. For example:

var importantDates = new Array( );
importantDates["dadsBirthday"] = "June 1";
importantDates["mumsBirthday"] = "January 16";

We may also use the dot operator, as follows:

arrayName.elementName = expression

In this case, elementName must be an identifier, not a string. For example:

var importantDates = new Array( );
importantDates.dadsBirthday = "June 1";
importantDates.mumsBirthday = "January 16";

Assuming that we know an element's identifier (for example, dadsBirthday in the importantDates array), we can access it in one of two ways:

var goShopping = importantDates["dadsBirthday"];
var goShopping = importantDates.dadsBirthday;

Just as is the case when assigning a value to a named element, when accessing an element with square brackets, elementName must be a string or an expression that yields a string. Likewise, when used with the dot operator, elementName must be an identifier (i.e., the element's name without quotes), not a string.

11.6.2. Removing Named Elements

To rid an array of an unwanted named element, we use the delete operator, which was introduced in Chapter 5, "Operators":

delete arrayName.elementName

Deleting a named element destroys both the element value and the element container, freeing up any memory being occupied by the element and its contents. (Contrast this with the delete operator's behavior for numbered elements, where it simply clears the value but leaves the container intact.)


11.5. Determining the Size of an Array		11.7. Adding Elements to an Array

11.6. Named Array Elements

11.6.1. Creating and Referencing Named Array Elements

11.6.2. Removing Named Elements