The use of data function in 1jquery
1.1 the data function is a data binding function in jQuery, and its syntax is data (key [, value]); if only key represents value, both of them have binding to represent value
take page.pageCurrent Property is bound to pagecurrent
The parameter has only one pagecurrent, which indicates the binding to the above function page.pageCurrent Value of
1.2 the reference of this in JavaScript
