测试：
var data = new Array(
{
id:1,
title:'title1',
content:'content1'
},
{
id:3,
title:'title2',
content:'content3'
},
{
id:2,
title:'title3',
content:'content2'
}
)
var tablesort = new tablesort(data)
var ret = tablesort.sort('id')
console.log(ret)
var ret = tablesort.sort('title')
console.log(ret)
var ret = tablesort.sort('id')
console.log(ret)
输出：
[ { id: 1, title: 'title1', content: 'content1' },
{ id: 2, title: 'title3', content: 'content2' },
{ id: 3, title: 'title2', content: 'content3' } ]
[ { id: 2, title: 'title3', content: 'content2' },
{ id: 3, title: 'title2', content: 'content3' },
{ id: 1, title: 'title1', content: 'content1' } ]
[ { id: 1, title: 'title1', content: 'content1' },
{ id: 2, title: 'title3', content: 'content2' },
{ id: 3, title: 'title2', content: 'content3' } ]
