taro实战：数据处理-百分比%

1.拿到总数 sum

 let sum = 0;
    let OrderCountData = data.map(item => {
      let obj = {};
      obj.name = item.servicetype;
      obj.num = item.num;
      sum += item.num;
      return obj;
    });

2.用总数sum/单个数量num

let arr = [];
    OrderCountData.map(item => {
      item.percent = Math.round((item.num / sum) * 10000) / 100+"%";
      item.a = "1";
      arr.push(item);
    });

3，化为%： Math.round((item.num / sum) * 10000) / 100+"%";

 Math.round((item.num / sum) * 10000) / 100+"%";