Find the Last Position of an ArrayList in Java

The lastIndexOf(Object obj) returns the position of the last occurrence of an element in an ArrayList.

public int lastIndexOf(Object obj): This method returns the index of the last occurrence of the object obj in the ArrayList. If the object doesn't exist, it returns -1.

In this example, we have an ArrayList of strings that contains a few duplicate elements. We look for the last index of a few elements using the method lastIndexOf().

import java.util.ArrayList; 

public class ArrayListLastIndexOf{ 
 
 public static void main(String[] args) {
 
 // Create an ArrayList< String> 
 ArrayList< String> arraylist = new ArrayList< String> (); 
 
 //add strings to ArrayList
 arraylist.add("obj1"); 
 arraylist.add("obj3"); 
 arraylist.add("obj5"); 
 arraylist.add("obj2"); 
 arraylist.add("obj1"); 
 arraylist.add("obj3"); 
 arraylist.add("obj1"); 
 arraylist.add("obj3"); 
 
 System.out.println("last occurrence of obj1: "+arraylist.lastIndexOf("obj1")); 
 System.out.println("last occurrence of obj3: "+arraylist.lastIndexOf("obj3")); 
 }
}

Runtime:

last occurrence of obj1:6
last occurrence of obj3:7