DoubleStream mapToInt() returns an IntStream consisting of the results of applying the given function to the elements of this stream.
Note : DoubleStream mapToInt() 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 :
IntStream mapToInt(DoubleToIntFunction mapper)
Parameters :
- IntStream : A sequence of primitive int-valued elements. This is the int primitive specialization of Stream.
- mapper : A stateless function to apply to each element.
Return Value : The function returns an IntStream consisting of the results of applying the given function to the elements of this stream.
Example 1 :
// Java code for IntStream mapToInt// (DoubleToIntFunction 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 a DoubleStream        DoubleStream stream = DoubleStream.of(2.3, 4.5, 6.4,                                              8.7, 10.4);          // Using IntStream mapToInt(DoubleToIntFunction mapper)        // to return an IntStream consisting of the        // results of applying the given function to        // the elements of this stream.        IntStream stream1 = stream.mapToInt(num -> (int)num);          // Displaying the elements in stream1        stream1.forEach(System.out::println);    }} |
Output :
2 4 6 8 10
Example 2 :
// Java code for IntStream mapToInt// (DoubleToIntFunction 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 a DoubleStream        DoubleStream stream = DoubleStream.of(2.3, 4.5, 6.4,                                              8.7, 10.4);          // Using IntStream mapToInt(DoubleToIntFunction mapper)        // to return an IntStream consisting of the        // results of applying the given function to        // the elements of this stream.        IntStream stream1 = stream.mapToInt(num -> (int)num - 10000);          // Displaying the elements in stream1        stream1.forEach(System.out::println);    }} |
Output :
-9998 -9996 -9994 -9992 -9990
Example 3 :
// Java code for IntStream mapToInt// (DoubleToIntFunction 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 a DoubleStream        DoubleStream stream = DoubleStream.of(1.3, 2.4, 3.4,                                              4.5, 5.7);          // Using IntStream mapToInt(DoubleToIntFunction mapper)        // to return an IntStream consisting of the        // results of applying the given function to        // the elements of this stream.        IntStream stream1 = stream.mapToInt(num -> (int)(num * num * num));          // Displaying the elements in stream1        stream1.forEach(System.out::println);    }} |
Output :
2 13 39 91 185
