How to concatenate two ArrayLists in java

In this tutorial, we'll look at how to merge two ArrayLists in java  with the method  addAll().  This method adds the two ArrayLists in a new ArrayList.

In the following code, two ArrayLists are merged into one:

import java.util.ArrayList; 
public class Fusion
{
 public static void main(String [] args)
 {
 //ArrayList A
 ArrayList listA=new ArrayList(); 
 listA.add("OA1"); 
 listA.add("OA2"); 
 listA.add("OA3"); 
 System.out.println("List A"); 
 for(String object: Alist){
 System.out.println(object); 
 }
 
 //ArrayList B
 ArrayList listB=new ArrayList(); 
 listB.add("OB1"); 
 listB.add("OB2"); 
 list B.add("OB3"); 
 System.out.println("\nList B"); 
 for(String object: B-list){
 System.out.println(object); 
 }

 //ArrayList that merges A and B
 ArrayList listAB= new ArrayList(); 
 listAB.addAll(listA); 
 listAB.addAll(listB); 
 System.out.println("\nList AB"); 
 //Show final list after merge
 for(String object: listAB){
 System.out.println(object); 
 }
 }
}

Output

List A
OA1
OA2
OA3

List B
OB1
 OB2
OB3

List AB
OA1
OA2
OA3
OB1
OB2
OB3