Highcharts 如何将数据 label 添加到系列的最后一个数据点

Question

I built a line chart: fiddle

Now I want to add a data label to the last data point of each series.

I tried with formatter:

if (this.x == visiblePoints[visiblePoints.length - 1].x)

but some series do not have a data point for the last date. How can I get the length of existing data?

Answer 1

As you rightly notice you need to use the formatter function for data labels. Use below code to check if the point is the last one.

series: {
  dataLabels: {
    enabled: true,
    formatter: function() {
      var seriesPoints = this.series.points;
      if (this.point === seriesPoints[seriesPoints.length - 1]) {
        return 'Last label point';
      }
    }
  }
}

---

Live demo: http://jsfiddle.net/BlackLabel/uqrt2j9d/

API Reference: https://api.highcharts.com/highcharts/plotOptions.series.dataLabels