interval property Null safety

double? interval

Axis interval value.

Using this, the axis labels can be displayed after certain interval value. By default, interval will be calculated based on the minimum and maximum values of the provided data.

Defaults to null.

Widget build(BuildContext context) {
   return Container(
       child: SfCartesianChart(
          primaryXAxis: NumericAxis(interval: 1),


final double? interval;