How to convert list to set in java with example program

• Java program to convert list to set.
• Convert ArrayList of string to HashSet in java example program
• How to convert List to Set in java 
• Set<String> strSet = new HashSet<String>(arrList);
• HashSet having a constructor which will take list as an argument.
• Lets see how to convert list to Set using java program.

#1: Java Example Program to Convert List to Set.

1. package com.instanceofjava;
2. 
   
3. import java.util.ArrayList;
4. import java.util.HashSet;
5. import java.util.Set;
6. 
   
7. public class ListToSet {
8. /**
9. * @author www.Instanceofjava.com
10. * @category interview questions
11. * 
12. * Description: Convert List to set in java with example program
13. *
14. */
15. public static void main(String[] args) {
17. ArrayList<String> arrList= new ArrayList<>();
18. arrList.add("Java");
19. arrList.add("List to String");
20. arrList.add("Example Program");
22. Set<String> strSet = new HashSet<String>(arrList);
24. System.out.println(strSet);
25. 
    
26. }
27. 
    
28. }

Output:

1. [Java, Example Program, List to String]

• Using java.util.stream we can convert List to set in java 8
• We can use java 8 java.util.stream.Collectors
• arrList.stream().collect(Collectors.toSet());

#2: Java Example program to convert List to Set using java 8.

1. package com.instanceofjava;
2. 
   
3. import java.util.ArrayList;
4. import java.util.Set;
5. import java.util.stream.Collectors;
6. 
   
7. public class ListToSet {
8. /**
9. * @author www.Instanceofjava.com
10. * @category interview questions
11. * 
12. * Description: Convert List to set in java with example program
13. *
14. */
15. public static void main(String[] args) {
17. ArrayList<String> arrList= new ArrayList<>();
18. arrList.add("Java");
19. arrList.add("List to String");
20. arrList.add("Example Program");
22. Set<String> strSet = arrList.stream().collect(Collectors.toSet());
24. System.out.println(strSet);
25. 
    
26. }
27. 
    
28. }

Output: