- Data Structure
- Networking
- RDBMS
- Operating System
- Java
- MS Excel
- iOS
- HTML
- CSS
- Android
- Python
- C Programming
- C++
- C#
- MongoDB
- MySQL
- Javascript
- PHP
- Physics
- Chemistry
- Biology
- Mathematics
- English
- Economics
- Psychology
- Social Studies
- Fashion Studies
- Legal Studies
- Selected Reading
- UPSC IAS Exams Notes
- Developer's Best Practices
- Questions and Answers
- Effective Resume Writing
- HR Interview Questions
- Computer Glossary
- Who is Who
Stream.concat() in Java
The concat() method of the Stream class in Java creates a lazily concatenated stream whose elements are all the elements of the first stream followed by all the elements of the second stream. The syntax is as follows −
concat(Stream<? extends T> a, Stream<? extends T> b)
Here, a is the first stream, whereas b is the second stream. T is the type of stream elements.
Example
Following is an example to implement the concat() method of the Stream class −
import java.util.*; import java.util.stream.IntStream; import java.util.stream.Stream; public class Demo { public static void main(String[] args) { Stream<String> streamOne = Stream.of("John"); Stream<String> streamTwo = Stream.of("Tom"); Stream.concat(streamOne, streamTwo).forEach(val -> System.out.println(val)); } }
Output
John Tom
Example
Let us now see another example wherein we are working on multiple streams −
import java.util.stream.Collectors; import java.util.stream.Stream; import static java.util.stream.Stream.*; public class Main { public static void main(String[] args) { Stream<Integer> streamOne = Stream.of(15, 40, 50); Stream<Integer> streamTwo = Stream.of(55, 70, 90); Stream<Integer> streamThree = Stream.of(110, 130, 150); Stream<Integer> streamFour = Stream.of(170, 200, 240, 300); Stream<Integer> res = Stream.concat(streamOne, concat(streamTwo, concat(streamThree, streamFour))); System.out.println( res.collect(Collectors.toList()) ); } }
Output
[15, 40, 50, 55, 70, 90, 110, 130, 150, 170, 200, 240, 300]
Advertisements