Stream forEach() method in Java with examples

Stream forEach(Consumer action) performs an action for each element of the stream. Stream forEach(Consumer action) is a terminal operation i.e, it may traverse the stream to produce a result or a side-effect.

Syntax :

void forEach(Consumer<? super T> action)

Where, Consumer is a functional interface
and T is the type of stream elements.

Note : The behavior of this operation is explicitly nondeterministic. Also, for any given element, the action may be performed at whatever time and in whatever thread the library chooses.

Example 1 : To perform print operation on each element of reversely sorted stream.

// Java code for forEach
// (Consumer action) in Java 8
import java.util.*;

class GFG {

    // Driver code
    public static void main(String[] args)
    {

        // Creating a list of Integers
        List<Integer> list = Arrays.asList(2, 4, 6, 8, 10);

        // Using forEach(Consumer action) to
        // print the elements of stream
        // in reverse order
        list.stream().sorted(Comparator.reverseOrder()).forEach(System.out::println);
    }
}

Output:

10
8
6
4
2

Example 2 : To perform print operation on each element of string stream.

// Java code for forEach
// (Consumer action) in Java 8
import java.util.*;

class GFG {

    // Driver code
    public static void main(String[] args)
    {

        // Creating a list of Strings
        List<String> list = Arrays.asList("GFG", "Geeks",
                                          "for", "GeeksforGeeks");

        // Using forEach(Consumer action) to
        // print the elements of stream
        list.stream().forEach(System.out::println);
    }
}

Output:

GFG
Geeks
for
GeeksforGeeks

Example 3 : To perform print operation on each element of reversely sorted string stream.

// Java code for forEach
// (Consumer action) in Java 8
import java.util.*;
import java.util.stream.Stream;

class GFG {

    // Driver code
    public static void main(String[] args)
    {

        // Creating a Stream of Strings
        Stream<String> stream = Stream.of("GFG", "Geeks",
                                          "for", "GeeksforGeeks");

        // Using forEach(Consumer action) to print
        // Character at index 1 in reverse order
        stream.sorted(Comparator.reverseOrder())
            .flatMap(str -> Stream.of(str.charAt(1)))
            .forEach(System.out::println);
    }
}

Output:

o
e
e
F