of these recipes (or your own variations on them) may be part of your
daily menu. If you don't use these constructions
frequently, let this chapter serve to refresh your memory, and give
you models to get you back on track when you need them.
have numerous nuances that are easy to forget over time. A couple of
concepts, such as exception handling and the
try/catch construction, are
also comparatively new in recent browsers. Scripters without formal
programming training tend to be rather loose in their attention to
detail in the error department—something that can come back to
bite you. On the other hand, the browser implementations of some of
the details of exception handling are far from compatible. If you
aren't yet using exception-handling techniques in
your scripts (perhaps the needs of backward-compatibility prevent
it), you should still get to know the concepts. As time goes on and
the full W3C DOM becomes implemented in browsers, the notion of
"safe scripting" will include
regular application of exception-handling practices.
This chapter ends with some suggestions about improving script
performance. Most scripts can scrape by with inefficiencies, but
larger projects that deal with complex document trees and substantial
amounts of hidden data delivered to the client must pay particular
attention to performance. You'll learn some
practices here that you should apply even to short scripts.