Passing null in Highcharts line graphs

Question

So I have to pass an array in javascript to the Highcharts y-axis and there are some cases in which for an x-axis value, there isn't supposed to be a y-axis value. So, the graph should join the previous point to the next point.

From my search, I found this solution on stack overflow -> missing value in highcharts line graph results in no line, just points

From the comments, apparently the null solution should be working but if you open that js fiddle, you'll see a broken line. At-least, that's what I'm seeing. Also, please see my jsfiddle file: Fiddle

$(function () {
    $('#container').highcharts({
        chart: {
            zoomType: 'xy'
        },
        title: {
            text: 'Average Monthly Temperature and Rainfall in Tokyo'
        },
        subtitle: {
            text: 'Source: WorldClimate.com'
        },
        xAxis: [{
            categories: ['Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun',
                'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec'],
            crosshair: true
        }],
        yAxis: [{ // Primary yAxis
            labels: {
                format: '{value}°C',
                style: {
                    color: Highcharts.getOptions().colors[1]
                }
            },
            title: {
                text: 'Temperature',
                style: {
                    color: Highcharts.getOptions().colors[1]
                }
            }
        }, { // Secondary yAxis
            title: {
                text: 'Rainfall',
                style: {
                    color: Highcharts.getOptions().colors[0]
                }
            },
            labels: {
                format: '{value} mm',
                style: {
                    color: Highcharts.getOptions().colors[0]
                }
            },
            opposite: true
        }],
        tooltip: {
            shared: true
        },
        legend: {
            layout: 'vertical',
            align: 'left',
            x: 120,
            verticalAlign: 'top',
            y: 100,
            floating: true,
            backgroundColor: (Highcharts.theme && Highcharts.theme.legendBackgroundColor) || '#FFFFFF'
        },
        series: [{
            name: 'Rainfall',
            type: 'spline',
            yAxis: 1,
            data: [49.9, 71.5, null, 129.2, 144.0, 176.0, 135.6, 148.5, 216.4, 194.1, 95.6, 54.4],
            tooltip: {
                valueSuffix: ' mm'
            }

        }, {
            name: 'Temperature',
            type: 'spline',
            data: [7.0, 6.9, 9.5, 14.5, 18.2, 21.5, 25.2, 26.5, 23.3, 18.3, 13.9, 9.6],
            tooltip: {
                valueSuffix: '°C'
            }
        }]
    });
});

You can see, there's a broken line here too if we pass null!

Answer 1

If you need to connect null values as well use connectNull:true

plotOptions: {
        series: {
            connectNulls: true
        }
    }

Updated fiddle here