Close

Java 8 Streams - Collectors.averagingInt Examples

Java 8 Streams Java Java API 

PreviousNext

Class:

java.util.stream.Collectors

java.lang.Objectjava.lang.Objectjava.util.stream.Collectorsjava.util.stream.CollectorsLogicBig

Method:

public static <T> Collector<T,?,Double> averagingInt(ToIntFunction<? super T> mapper)

Returns a Collector that produces the arithmetic mean of an integer-valued function applied to the input elements. If no elements are present, the result is 0.


Examples


The method Collectors#averagingInt converts each stream elements to int per user provided mapper function and returns the arithmetic mean of those integers. 

package com.logicbig.example.collectors;


import java.math.BigDecimal;
import java.util.stream.Collectors;
import java.util.stream.Stream;

public class AveragingIntExample {
    public static void main (String[] args) {
        Stream<BigDecimal> s = Stream.iterate(
                            BigDecimal.ONE, bigDecimal ->
                                                bigDecimal.add(BigDecimal.ONE))
                                     .limit(10).peek(System.out::println);

        Double d = s.collect(Collectors.averagingInt(BigDecimal::intValue));
        System.out.println("average: " + d);
    }
}

Output

1
2
3
4
5
6
7
8
9
10
average: 5.5
Original Post

See Also