DoubleSummaryStatistics (in java.util) is a collector used in stream processing that automatically computes count, sum, min, average, and max of a stream of double values.

• When processing numerical data streams (like scores, prices, or measurements).
• Quickly summarizing statistics without manual aggregation.
• Useful in analytics, reporting, and dashboards.

import java.util.DoubleSummaryStatistics;
import java.util.stream.DoubleStream;

public class SummaryStatsExample {
    public static void main(String[] args) {
        DoubleStream scores = DoubleStream.of(86.5, 90.0, 75.2, 88.8);

        DoubleSummaryStatistics stats = scores.summaryStatistics();

        System.out.println("Count: " + stats.getCount());
        System.out.println("Sum: " + stats.getSum());
        System.out.println("Min: " + stats.getMin());
        System.out.println("Average: " + stats.getAverage());
        System.out.println("Max: " + stats.getMax());
    }
}

Count: 4
Sum: 340.5
Min: 75.2
Average: 85.125
Max: 90.0

• Also available for IntSummaryStatistics and LongSummaryStatistics.
• Ideal when using Stream API to analyze numeric datasets.
• Eliminates the need to manually track all individual values.