IntStream flatMap(IntFunction mapper) in Java
Last Updated :
06 Dec, 2018
IntStream flatMap(IntFunction mapper) returns a stream consisting of the results of replacing each element of this stream with the contents of a mapped stream produced by applying the provided mapping function to each element. This is an 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.
Note : Each mapped stream is closed after its contents have been placed into this stream. If a mapped stream is null, an empty stream is used, instead.
Syntax :
IntStream flatMap(IntFunction<? extends IntStream> mapper)
Parameters :
- IntStream : A sequence of primitive int-valued elements.
- IntFunction : A function that accepts an int-valued argument and produces a result.
- mapper : A stateless function which is applied to each element and the function returns the new stream.
Return Value : IntStream flatMap(IntFunction mapper) returns a stream by a mapped stream using mapping function.
Example 1 : Using IntStream flatMap() to get the cube of elements of IntStream.
import java.util.*;
import java.util.stream.IntStream;
class GFG {
public static void main(String[] args)
{
IntStream stream1 = IntStream.of( 4 , 5 , 6 , 7 );
IntStream stream2 = stream1.flatMap(num
-> IntStream.of(num * num * num));
stream2.forEach(System.out::println);
}
}
|
Output :
64
125
216
343
Example 2 :Using IntStream flatMap() to get the count of set bits in binary representation of elements of IntStream.
import java.util.*;
import java.util.stream.IntStream;
class GFG {
public static void main(String[] args)
{
IntStream stream1 = IntStream.of( 49 , 64 , 81 , 100 );
IntStream stream2 = stream1.flatMap(num
-> IntStream.of(Integer.bitCount(num)));
stream2.forEach(System.out::println);
}
}
|
Output :
3
1
3
3
Like Article
Suggest improvement
Share your thoughts in the comments
Please Login to comment...