Related Articles

Related Articles

IntStream mapToDouble() in Java
  • Last Updated : 06 Dec, 2018

IntStream mapToDouble() returns a DoubleStream consisting of the results of applying the given function to the elements of this stream.

Note : IntStream mapToDouble() is a intermediate operation. These operations are always lazy. Intermediate operations are invoked on a Stream instance and after they finish their processing, they give a Stream instance as output.
Syntax :

DoubleStream mapToDouble(IntToDoubleFunction mapper)

Parameters :

  1. DoubleStream : A sequence of primitive double-valued elements. This is the double primitive specialization of Stream.
  2. mapper : A stateless function to apply to each element.

Return Value : The function returns a DoubleStream consisting of the results of applying the given function to the elements of this stream.

Example 1 :



filter_none

edit
close

play_arrow

link
brightness_4
code

// Java code for DoubleStream mapToDouble
// (IntToDoubleFunction mapper)
import java.util.*;
import java.util.stream.IntStream;
import java.util.stream.DoubleStream;
  
class GFG {
  
    // Driver code
    public static void main(String[] args)
    {
        // Creating an IntStream
        IntStream stream = IntStream.of(2, 4, 6, 8, 10);
  
        // Using DoubleStream mapToLong(IntToDoubleFunction mapper)
        // to return a DoubleStream consisting of the
        // results of applying the given function to
        // the elements of this stream.
        DoubleStream stream1 = stream.mapToDouble(num -> (double)num);
  
        // Displaying the elements in stream1
        stream1.forEach(System.out::println);
    }
}

chevron_right


Output :

2.0
4.0
6.0
8.0
10.0

Example 2 :

filter_none

edit
close

play_arrow

link
brightness_4
code

// Java code for DoubleStream mapToDouble
// (IntToDoubleFunction mapper)
import java.util.*;
import java.util.stream.IntStream;
import java.util.stream.DoubleStream;
  
class GFG {
  
    // Driver code
    public static void main(String[] args)
    {
        // Creating an IntStream
        IntStream stream = IntStream.range(5, 10);
  
        // Using DoubleStream mapToLong(IntToDoubleFunction mapper)
        // to return a DoubleStream consisting of the
        // results of applying the given function to
        // the elements of this stream.
        DoubleStream stream1 = stream.mapToDouble(num -> (double)num / 3);
  
        // Displaying the elements in stream1
        stream1.forEach(System.out::println);
    }
}

chevron_right


Output :

1.6666666666666667
2.0
2.3333333333333335
2.6666666666666665
3.0

Example 3 :

filter_none

edit
close

play_arrow

link
brightness_4
code

// Java code for DoubleStream mapToDouble
// (IntToDoubleFunction mapper)
import java.util.*;
import java.util.stream.IntStream;
import java.util.stream.DoubleStream;
  
class GFG {
  
    // Driver code
    public static void main(String[] args)
    {
        // Creating an IntStream
        IntStream stream = IntStream.range(5, 10);
  
        // Using DoubleStream mapToLong(IntToDoubleFunction mapper)
        // to return a DoubleStream consisting of the
        // results of applying the given function to
        // the elements of this stream.
        DoubleStream stream1 = stream.mapToDouble(Math::sin);
  
        // Displaying the elements in stream1
        stream1.forEach(System.out::println);
    }
}

chevron_right


Output :

-0.9589242746631385
-0.27941549819892586
0.6569865987187891
0.9893582466233818
0.4121184852417566

Attention reader! Don’t stop learning now. Get hold of all the important Java Foundation and Collections concepts with the Fundamentals of Java and Java Collections Course at a student-friendly price and become industry ready.




My Personal Notes arrow_drop_up
Recommended Articles
Page :