DoubleStream count() returns the count of elements in the stream. DoubleStream count() is present in java.util.stream.DoubleStream. This is a special case of a reduction i.e, it takes a sequence of input elements and combines them into a single summary result.
Syntax :
long count()
Note : This is a terminal operation i.e, it may traverse the stream to produce a result or a side-effect. After the terminal operation is performed, the stream pipeline is considered consumed, and can no longer be used.
Example 1 : Count the elements in DoubleStream.
// Java code for DoubleStream count()// to count the number of elements in// given streamimport java.util.*;import java.util.stream.DoubleStream;  class GFG {      // Driver code    public static void main(String[] args)    {        // creating a DoubleStream        DoubleStream stream = DoubleStream.of(2.3, 3.4, 4.5,                                         5.6, 6.7, 7.8, 8.9);          // storing the count of elements        // in a variable named total        long total = stream.count();          // displaying the total number of elements        System.out.println(total);    }} |
Output:
7
Example 2 : Count distinct elements in DoubleStream.
// Java code for DoubleStream count()// to count the number of distinct// elements in given streamimport java.util.*;import java.util.stream.DoubleStream;  class GFG {      // Driver code    public static void main(String[] args)    {        // creating a DoubleStream        DoubleStream stream = DoubleStream.of(2.2, 3.3, 4.4,                                        4.4, 7.6, 7.6, 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
