JAVA EE: FlatMap method of Java 8 Stream | Java 8 streams tutorial | Java 8 streams

Tuesday 29 August 2017

FlatMap method of Java 8 Stream | Java 8 streams tutorial | Java 8 streams | Streams in Java 8

Click here to watch in Youtube :
https://www.youtube.com/watch?v=3jWqXZBA8pY&list=UUhwKlOVR041tngjerWxVccw

StreamFlatMapDemo1.java

import java.util.Arrays;

public class StreamFlatMapDemo1
{
    public static void main(String[] args)
    {
        Integer[][] integerArray = { { 1, 2 }, { 3, 4 }, { 5, 6 } };

        /*
         * Stream.flatMap()
         *
         * It returns a stream of object after applying mapping
         * function on each element and then flattens the result.
         */
        Arrays.stream(integerArray).flatMap(row -> Arrays.stream(row))
                                   .forEach(s -> System.out.print(s + " "));
    }
}

Output

1 2 3 4 5 6

StreamFlatMapDemo2.java

import java.util.Arrays;

public class StreamFlatMapDemo2
{
    public static void main(String[] args)
    {
        Integer[][] integerArray = { { 1, 2 }, { 3, 4 }, { 5, 6 } };

        /*
         * Stream.flatMap()
         *
         * It returns a stream of object after applying mapping
         * function on each element and then flattens the result.
         */
        Arrays.stream(integerArray).flatMap(row -> Arrays.stream(row))
                                   .filter(num -> num % 2 == 1)
                                   .forEach(s -> System.out.print(s + " "));
    }
}