Java ArrayList lastIndexOf(Object 0bj) Method example

The method lastIndexOf(Object obj) returns the index of last occurrence of the specified element in the ArrayList. It returns -1 if the specified element does not exist in the list.

public int lastIndexOf(Object obj)
This would return the index of last Occurrence of element Obj in the ArrayList.

Example

In the below example we have an Integer ArrayList which has few duplicate elements. We are fetching the last index of few elements using lastIndexof method.

package beginnersbook.com;
import java.util.ArrayList;
public class LastIndexOfExample {
  public static void main(String args[]) {
      //ArrayList of Integer Type
      ArrayList<Integer> al = new ArrayList<Integer>();
      al.add(1);
      al.add(88);
      al.add(9);
      al.add(17);
      al.add(17);
      al.add(9);
      al.add(17);
      al.add(91);
      al.add(27);
      al.add(1);
      al.add(17);

      System.out.println("Last occurrence of element 1: "+al.lastIndexOf(1));
      System.out.println("Last occurrence of element 9: "+al.lastIndexOf(9));
      System.out.println("Last occurrence of element 17: "+al.lastIndexOf(17));
      System.out.println("Last occurrence of element 91: "+al.lastIndexOf(91));
      System.out.println("Last occurrence of element 88: "+al.lastIndexOf(88)); 
   }
}

Output:

Last occurrence of element 1: 9
Last occurrence of element 9: 5
Last occurrence of element 17: 10
Last occurrence of element 91: 7
Last occurrence of element 88: 1