2. Get the elements in common between two lists - java 8

2. Get the elements in common between two lists - java 8

 

Tools:

-JDK 8
-CoderPad/Sanbox

Solution:

import java.io.*;
import java.util.*;
import java.util.stream.Collectors;
import java.util.function.Function;
class Solution
 {
   public static void main(String[] args)
   {
     //Init a
     List<Integer> a = new ArrayList<Integer>();
     a.add(1);
     a.add(3);
     a.add(4);
     a.add(6);
     a.add(8);
     a.add(9);

     //Init b
     List<Integer> b= new ArrayList<Integer>();
     b.add(1);
     b.add(2);
     b.add(3);
     b.add(5);
     b.add(6);
     b.add(8);

     List<Integer> commons = commonElements(a,b);
     //Print Result
     System.out.print("The elements in common between a and b are :"+ commons);
   }
  
   //method that find common elements between two lists
   public static List<Integer> commonElements(List<Integer> a,List<Integer>b)
   {
     List<Integer> result = new ArrayList<Integer>();
     //Maybe you would need to override equals and hash method for complex objects
     //This method find an element of a in b
     //This can be work in java 7 and less by replacing forEach to for block
     a.forEach(item->
                    {
                      if(b.contains(item))
                         result.add(item);
                    });
     return result;
   }
 }

Comment:

Leave a comment if you have a doubt or you have a better solution, also if you have any suggestion