JQuery Training

Use the newest version jQuery
Use the right selector
Understand the parent and children

$parent.find(‘.child’)
效率最高
$('#parent .child')
$('#parent .child') 
效率差

Don’t abuse jQuery
Use cache
Chaining
Event delegation

delegate()  代理子元素的动作， 效率高
$('#nav').delegate('a', 'click', function(e) {
 e.preventDefault();
});

DOM Event Model

1, Capture phase
2, target phase
3, bubble phase

Diff between click(), delegate() and live()
Don’t change DOM frequently
每次用appendTo方式加上节点，都会改变dom的结构，浏览器需要重画html
这时可以用detach 等很多appendTo都执行好了，再add回DOM。

Understand loops
Avoid construct new jQuery objects unless necessary

chrome控制台
console.log("aaa")

Js performance compare site:
http://jsperf.com/

Jquery API study site:
http://api.jquery.com/