DoubleStream distinct() in Java with examples

DoubleStream distinct() is a method in java.util.stream.DoubleStream. This method returns a stream consisting of the distinct elements. This is a stateful intermediate operation i.e, it may incorporate state from previously seen elements when processing new elements. They may need to process the entire input before producing a result. For example, one cannot produce any results from sorting a stream until one has seen all elements of the stream.

Syntax :

DoubleStream distinct()

Where, DoubleStream is a sequence of 
primitive long-valued elements.

Example 1 : Printing distinct elements of Double stream.

// Java code for DoubleStream distinct()
import java.util.*;
import java.util.stream.DoubleStream;

class GFG {

    // Driver code
    public static void main(String[] args)
    {
        // creating a stream
        DoubleStream stream = DoubleStream.of(2.2, 3.3, 3.3,
                                        5.6, 6.7, 6.7, 8.0);

        // Displaying only distinct elements
        // using the distinct() method
        stream.distinct().forEach(System.out::println);
    }
}

Output :

2.2
3.3
5.6
6.7
8.0

Example 2 : Counting value of distinct elements in a Double stream.

// Java code for DoubleStream distinct() method
// to count the number of distinct
// elements in given stream
import java.util.*;
import java.util.stream.DoubleStream;

class GFG {

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

        // creating a stream
        DoubleStream stream = DoubleStream.of(2.2, 3.3, 3.3,
                                         5.6, 6.7, 6.7, 8.0);

        // storing the count of distinct elements
        // in a variable named total
        long total = stream.distinct().count();

        // displaying the total number of elements
        System.out.println(total);
    }
}

Output :

5