微信小程序中修改数据(页面数据和数组数据)的代码实现

 let pages = getCurrentPages();//当前页面
    let prevPage = pages[pages.length - 2];//上一页面
    prevPage.setData({//直接给上移页面赋值
      selAddress: true
    });

数组部分：
comdata[
{xhid:8,title:啦啦啦,read_num:100,share_num:20},
{xhid:9,title:嘻嘻嘻,read_num:24,share_num:4},
{xhid:20,title:嘻嘻嘻2,read_num:11,share_num:4},
{xhid:27,title:嗯嗯嗯12,read_num	:8,share_num:4},
{xhid:23,title:阿萨飒飒2,read_num:41,share_num:7}
]
代码如下：
var index=0;
var up = "comdata[" + index + "].share_num";
          var newp = ++that.data[0].share_num;
        that.setData({
            [up]:newp
})

A页面传给B页面share_num和当前的index

在B页面onload赋给
 that.setData({
      item_index:options.index,
      share_num:options.share_num
    })

然后修改代码：

 let pages = getCurrentPages();//当前页面
          let prevPage = pages[pages.length - 2];//上一页面
          var index = that.data.item_index;
          var up = "comdata[" + index + "].share_num";
          var newp = ++that.data.share_num;
          prevPage.setData({//直接给上移页面赋值
            [up]: newp
          });