JsBench

In the search for techniques to produce truly blazing JavaScript, I've found lots of conflicting and downright misinformation on the web. When Googe's App Engine was released, I decided to kill two birds with one stone: (1) play with App Engine and (2) create a tool for sharing real world cross browser JavaScript benchmarks.

Try it out:
http://jsbench.appspot.com/



If you aren't sure how to get started, check out some of my experiments.

For instance, did you know that using the Boolean() constructor is perhaps the slowest way to create a boolean? In some cases it can be as much as an order of magnitude slower than alternate methods.
http://jsbench.appspot.com/#suite=agdqc2JlbmNocgwLEgVTdWl0ZRiaAgw

Also, if you've been using a for..in loops when they aren't necessary, your code is probably running more than ten times slower than it has to if you'd used a typical for-loop and cached the length.
http://jsbench.appspot.com/#suite=agdqc2JlbmNocgsLEgVTdWl0ZRgNDA

Oh, and the last bit for now is that you better not even think of omitting the "var" statement when creating a new variable. Doing so could be slowing you down by two orders of magnitude!
http://jsbench.appspot.com/#suite=agdqc2JlbmNocgwLEgVTdWl0ZRjqAgw

Look for some more specific, in depth studies to come. What examples can you come up with?