Java 8 initialize set with values with an example program

• We can initialize set while defining by passing values to constructor.
• For example to initialize HashSet we can use Arrays.asList(value1,value2).
• Set<Integer> hashset = new HashSet<>(Arrays.asList(12, 13));

#1: Java Example program to initialize set without using java 8

1. import java.util.Arrays;
2. import java.util.HashSet;
3. import java.util.Set;
4. /**
5.  * @author www.Instanceofjava.com
6.  * @category interview questions
7.  * 
8.  * Description: Initialize set 
9.  *
10.  */
11. public class InitializeSet {
12. 
    
13. public static void main(String[] args) {
14. 
    
15. Set<Integer> hashset = new HashSet<>(Arrays.asList(12, 13));
16. System.out.println(hashset);
17. }
18. 
    
19. }

Output:

1. [12, 13]

• We can initialize set in java 8 using Stream.
• Stream.of("initialize", "set").collect(Collectors.toSet());

#2: Java Example program to initialize set without using java 8

2. import java.util.Set;
3. import java.util.stream.Collectors;
4. import java.util.stream.Stream;
5. /**
6.  * @author www.Instanceofjava.com
7.  * @category interview questions
8.  * 
9.  * Description: Initialize set using java 8 Stream
10.  *
11.  */
12. public class InitializeSet {
13. 
    
14. public static void main(String[] args) {
15. 
    
16. Set<String> set = Stream.of("initialize", "set").collect(Collectors.toSet());
17. System.out.println(set);
18. }
19. 
    
20. }

Output:

1. [set, initialize]

• We can initialize Set in java 8 by creating stream from an Array and list

#3: Java Example program to initialize set without using java 8