jQuery 10 performance tips

This is a summary of 10 jQuery performance tips from http://addyosmani.com/jqprovenperformance/

1. Use the latest jquery release
2. Know your selectors (ID, element, class, pseudo & attribute)
3. Use .find() -> $parent.find('.child').show() is the fastest than others (scoped selector)
4. Don't use jQuery unless it's absolutely necessary -> this.id is fater than $(this).attr('id')
5. Caching -> storing the result of a selection for later re-use, no repeat selection
6. Chaining
7. Event delegation -> if possible, use delegate instead of bind and live
8. Each DOM insertion is costly -> keep the use of .append(), .insertBefore() and .insertAfter() to a minimum; .data() is better than .text() or .html(); $.data('#elem', key, value) is faster than $('elem').data(key, value)
9. Avoid loops -> Javascript for or while loop is faster than jQuery .each()
10. Avoid constructing new jQuery object unless ncessary -> use $.method() rather than $.fn.method(); $.text($text) is faster than $text.text(), $.data() is faster than $().data

Update (11/30/2011):
In recent jQuery performance discussion, I summarized the following points based on different messages.

1. Scope jquery selectors (use find)
2. Know selectors performance => ID > element (tag) > class > pseudo & attribute
3. Avoid loops =>  if loop is inevitable, consider for/while > $.each()  if possible
4. Cache the result of a selection for later use (using local variables if possible)
5. DOM operation is expensive (esp. in a loop)
6. Don't use $ unless it's necessary => this.name > $(this).attr('name’)