IntStream mapToDouble() in Java
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 :
- DoubleStream : A sequence of primitive double-valued elements. This is the double primitive specialization of Stream.
- 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 :
// 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); }} |
Output :
2.0 4.0 6.0 8.0 10.0
Example 2 :
// 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); }} |
Output :
1.6666666666666667 2.0 2.3333333333333335 2.6666666666666665 3.0
Example 3 :
// 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); }} |
Output :
-0.9589242746631385 -0.27941549819892586 0.6569865987187891 0.9893582466233818 0.4121184852417566
