echarts 图表上数值显示

 lineCharts.setOption({
          tooltip: {
            trigger: "axis",
            formatter: function(data) {
              var res = [];
              data.forEach(element => {
                element.value = (element.value * 1.0).toFixed(2);
                res.push( element.marker + "" + element.seriesName + ":" + element.value +"," + element.name);
              });
              return res.join("
");
            }
          },
          grid: { containLabel: true },
          toolbox: {
            feature: { saveAsImage: {} }
          },
          legend: {
            y: "bottom",
            x: "center",
            data: [1,2]
          },
          xAxis: {
            type: "category",
            boundaryGap: false,
            data: ["A","B","C","D","E"]
          },
          yAxis: { type: "value" },
          series: [{'name':1,"type":"line","data":[1,2,3,4,5]},{'name':2,"type":"line", "data":[5,4,3,2,1]}]
        });