Optimizing Flash and AIR applications for mobile

Looking for ways to build incredibly speedy Flash or AIR applications for mobile devices? If so, look no further than Optimizing Performance for the Flash Platform. Released last year, this guide is brimming with valuable tidbits, provided in part by Adobe’s own Thibault Imbert. It offers tips for optimizing performance on mobile devices, desktops and TVs, ranging from basic ActionScript best practices to sophisticated graphics rendering techniques.

Here are a couple of simple ActionScript optimizations from the Miscellaneous optimizations section of the ActionScript 3.0 performance chapter.

Avoid evaluating statements in loops
Another optimization can be achieved by not evaluating a statement inside a loop. The following code iterates over an array, but is not optimized because the array length is evaluated for each iteration:

for (var i:int = 0; i< myArray.length; i++)

It is better to store the value and reuse it:

var lng:int = myArray.length;
for (var i:int = 0; i< lng; i++)

Use reverse order for while loops
A while loop in reverse order is faster than a forward loop:

var i:int = myArray.length;
while (--i > -1)

These tips provide a few ways to optimize ActionScript, showing how a single line of code can affect performance and memory. Many other ActionScript optimizations are possible. For more information,
see http://www.rozengain.com/blog/2007/05/01/some-actionscript-30-optimizations.