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.

989

Appendix D

APPENDIX D

Differences from ECMA-262

and JavaScript

Naturally, this book focuses on the intricacies of ActionScript, but if you own

O’Reilly’s well-known JavaScript: The Definitive Guide, you’ll notice that the refer-

ence section of the two books share many similarities.

Although ActionScript, like JavaScript, is based on the ECMA-262 standard, certain

differences were necessitated by the constraints of Player size and backward compati-

bility. If you’re porting code from JavaScript, JScript, or another ECMA-262–based

language, you’ll find Table D-1 valuable. It summarizes the intentional differences

between ECMA-262, JavaScript, and ActionScript (for Flash 5 and later). Likewise, if

you’re porting ActionScript to another language, you’ll be better able to avoid the

pitfalls caused by ActionScript’s deviation from the ECMA-262 standard.

Table D-1 reflects the intentional differences between Flash ActionScript and the

ECMA-262 standard. It does not reflect any bugs that may exist in its attempted

implementation of the standard. Furthermore, Table D-1 reflects ActionScript’s

behavior when the

#strict pragma is not being used. (The undocumented, unsup-

ported

#strict pragma was intended to enhance ActionScript’s conformance with

the ECMA-262 standard. However, the

#strict pragma ...