How to join or combine two ArrayList

For combining or joining two ArrayList will be using addAll() method
Eg:

public static void main(String[]args){

//creation of Arraylist 1 with string arguments

//adding elements to Arraylist 1

ArrayList<String> al=new ArrayList<String>();

al.add("India");

al.add("US");

//Displaying elements of Arraylist

System.out.println(al);

//creation of Arraylist 2 with string arguments

ArrayList<String> al=new ArrayList<String>();

/adding elements to Arraylist 2

al2.add("Australia");

al2.add("Germany");

al2.add("Europe");
al.addAll(al2);

}

Output:[India,US,Australia,Germany,Europe]