How to use DoubleSummaryStatistics in Java

When to use `DoubleSummaryStatistics`

For double values, DoubleSummaryStatistics is used to collect counts, min, max, total, and average statistics.

This class is intended to operate with streams, although it is not required. It was introduced in Java 8.

How to import `DoubleSummaryStatistics`

DoubleSummaryStatistics is defined in the util package in Java, so you must import the util package before using the DoubleSummaryStatistics class, as shown below:

import java.util.DoubleSummaryStatistics;

Methods

Method Name	Description
`accept(double value)`	Another value is added to the summary information.
`combine(DoubleSummaryStatistics other)`	The state of another DoubleSummaryStatistics object is merged using this method
`getCount()`	Returns the total number of values that have been seen so far.
`getSum()`	Returns the sum of all values observed so far, or zero if none have been seen
`getMin()`	Returns the smallest recorded value
`getMax()`	Returns the largest recorded value
`getAverage()`	Returns the arithmetic mean of all values seen so far, or zero if none have been seen.

import java.util.ArrayList;
import java.util.DoubleSummaryStatistics;
import java.util.List;
public class Main {
    public static void main(String args[])
    {
        List<Double> doubleList = new ArrayList<>();
        doubleList.add(12.4);
        doubleList.add(100.0);
        doubleList.add(136.5);
        doubleList.add(1000.2345);
        doubleList.add(200.34);
        doubleList.add(1.1);
        DoubleSummaryStatistics doubleSummaryStatistics = new DoubleSummaryStatistics();
        for(double d: doubleList) doubleSummaryStatistics.accept(d);
        System.out.println("Count of the elements - " + doubleSummaryStatistics.getCount());
        System.out.println("Sum of the elements - " + doubleSummaryStatistics.getSum());
        System.out.println("Minimum element - " + doubleSummaryStatistics.getMin());
        System.out.println("Maximum element - " + doubleSummaryStatistics.getMax());
        System.out.println("Average of the elements - " + doubleSummaryStatistics.getAverage());
    }
}

import java.util.ArrayList;
import java.util.DoubleSummaryStatistics;
import java.util.List;
import java.util.stream.Collectors;
public class Main {
    public static void main(String args[])
    {
        List<Double> doubleList = new ArrayList<>();
        doubleList.add(12.4);
        doubleList.add(100.0);
        doubleList.add(136.5);
        doubleList.add(1000.2345);
        doubleList.add(200.34);
        doubleList.add(1.1);
        DoubleSummaryStatistics doubleSummaryStatistics = doubleList.stream().collect(Collectors.summarizingDouble(e -> e));
        System.out.println("Count of the elements - " + doubleSummaryStatistics.getCount());
        System.out.println("Sum of the elements - " + doubleSummaryStatistics.getSum());
        System.out.println("Minimum element - " + doubleSummaryStatistics.getMin());
        System.out.println("Maximum element - " + doubleSummaryStatistics.getMax());
        System.out.println("Average of the elements - " + doubleSummaryStatistics.getAverage());
    }
}