nullFormat property

String? nullFormat
getter/setter pair

Format for points with the value of null. Works analogously to format. nullFormat can be applied only to series which support displaying null points. heatmap and tilemap supports nullFormat by default while the following series requires #series.nullInteraction set to true: line, spline, area, area-spline, column, bar, and timeline. Does not work with series that don't display null points, like pie.

API Docs: https://api.highcharts.com/highcharts/series.treemap.dataLabels.nullFormat

Implementation

String? nullFormat;