jQuery常用方法

1、extend方法：
extend({dest},sr1,sr2)将sr1,sr2,sr3...合并到dest中,返回值为合并后的后的dest
extend(boll是否深度复制,{},sr1,sr2) 如：$.extend(bool,{ name: "John", location: {city: "Boston",county:"USA"} }, { last: "Resig", location: {state: "MA",county:"China"} } ); true:result:result={name:"John",last:"Resig", location:{city:"Boston",state:"MA",county:"China"}} false:result={name:"John",last:"Resig",location:{state:"MA",county:"China"}}

2、data():方法向被选元素附加数据，或者从被选元素获取数据。

3、