Java ArrayList addAll(int index, Collection c) Method example

In the last tutorial we have shared the example of addAll(Collection c) method which is used for adding all the elements of Collection c at the end of list. Here we will see another variant add(int index, Collection c) which adds all the elements of c at the specified index of a list.

public boolean addAll(int index, Collection c)

Example

In this example we have two ArrayList of String type and we are adding the element of second arraylist at the 3rd position(index =2) of first arraylist.

package beginnersbook.com;
import java.util.ArrayList;
public class ExampleOfaddAllMethod {
   public static void main(String[] args) {
       // ArrayList1 
       ArrayList<String> al = new ArrayList<String>();
       al.add("Apple");
       al.add("Orange");
       al.add("Grapes");
       al.add("Mango");
       System.out.println("ArrayList1 before addAll:"+al);

       //ArrayList2 
       ArrayList<String> al2 = new ArrayList<String>();
       al2.add("Fig");
       al2.add("Pear");
       al2.add("Banana");
       al2.add("Guava");
       System.out.println("ArrayList2 content:"+al2);

       //Adding ArrayList2 in ArrayList1 at 3rd position(index =2)
       al.addAll(2, al2);
       System.out.println("ArrayList1 after adding ArrayList2 at 3rd Pos:\n"+al);
   }
}

Output:

ArrayList1 before addAll:[Apple, Orange, Grapes, Mango]
ArrayList2 content:[Fig, Pear, Banana, Guava]
ArrayList1 after adding ArrayList2 at 3rd Pos:
[Apple, Orange, Fig, Pear, Banana, Guava, Grapes, Mango]

Reference:

http://docs.oracle.com/javase/6/docs/api/java/util/ArrayList.html#addAll(int, java.util.Collection)