DoubleStream findAny() with examples

DoubleStream findAny() returns an OptionalDouble (a container object which may or may not contain a non-null value) describing some element of the stream, or an empty OptionalDouble if the stream is empty.

Syntax :

OptionalDouble findAny()

Parameters :

1. OptionalDouble : A container object which may or may not contain a non-null value.

Return Value : The function returns an OptionalDouble describing some element of this stream, or an empty OptionalDouble if the stream is empty.

Note : findAny() is a terminal-short-circuiting operation of Stream interface. This method returns any first element satisfying the intermediate operations. This is a short-circuit operation because it just needs ‘any’ first element to be returned and terminate the rest of the iteration.

Example 1 : findAny() method on Double Stream.

// Java code for DoubleStream findAny()
// which returns an OptionalDouble describing
// some element of the stream, or an
// empty OptionalDouble if the stream is empty.
import java.util.*;
import java.util.stream.DoubleStream;

class GFG {

    // Driver code
    public static void main(String[] args)
    {
        // Creating an DoubleStream
        DoubleStream stream = DoubleStream.of(6.3, 7.4, 8.5, 9.6);

        // Using DoubleStream findAny() to return
        // an OptionalDouble describing some element
        // of the stream
        OptionalDouble answer = stream.findAny();

        // if the stream is empty, an empty
        // OptionalDouble is returned.
        if (answer.isPresent()) {
            System.out.println(answer.getAsDouble());
        }
        else {
            System.out.println("no value");
        }
    }
}

Output :

6.3

Note : The behavior of DoubleStream findAny() operation is explicitly non-deterministic i.e, it is free to select any element in the stream. Multiple invocations on the same source may not return the same result.

Example 2 : findAny() method to return the elements divisible by 4, in a non-deterministic way.

// Java code for DoubleStream findAny()
// which returns an OptionalDouble describing
// some element of the stream, or an
// empty OptionalDouble if the stream is empty.
import java.util.OptionalDouble;
import java.util.stream.DoubleStream;

class GFG {

    // Driver code
    public static void main(String[] args)
    {
        // Creating an DoubleStream
        DoubleStream stream = DoubleStream.of(4.4, 5.6,
                    8.4, 10.2, 12.0, 16.0).parallel();

        // Using DoubleStream findAny().
        // Executing the source code multiple times
        // may not return the same result.
        // Every time you may get a different
        // Double value which is divisible by 4.
        stream = stream.filter(num -> num % 4 == 0);

        OptionalDouble answer = stream.findAny();
        if (answer.isPresent()) {
            System.out.println(answer.getAsDouble());
        }
    }
}

Output :

16.0