Java 8 - stream average

In this article, we would like to show you how to find stream average in Java 8.

Quick solution:

// example stream
Stream<Integer> streamOfIntegers = Stream.of(1, 2, 3);

streamOfIntegers
        .mapToDouble(x -> x)
        .average()
        .ifPresent(avg -> System.out.println("average = " + avg));  // 2.0

Practical example

In this example, we use:

• mapToInt() - to map each element of the stream to int,
• average() - to calculate the average element of the stream,
• ifPresent() - to display the average if the value is present.

import java.util.stream.Stream;

public class Example {

    public static void main(String[] args) {
        // example stream
        Stream<Integer> streamOfIntegers = Stream.of(1, 2, 3);

        // find stream average
        streamOfIntegers
                .mapToInt(x -> x)
                .average()
                .ifPresent(avg -> System.out.println("average = " + avg));
    }
}

Output:

average = 2.0

References

• Java 8 documentation - mapToInt()
• Java 8 documentation - average()
• Java 8 documentation - ifPresent()