The lastIndexOf() method of java.util.AbstractSequentialList class is used to return the index of the first occurrence of the specified element in this list, or -1 if this list does not contain the element. More formally, returns the lowest index i such that (o==null ? get(i)==null : o.equals(get(i))), or -1 if there is no such index.
Syntax:
public int lastIndexOf(Object o)
Parameters: This method takes Object o as parameter which is the element to search for.
Return Value: This method returns the index of the first occurrence of the specified element in this list, or -1 if this list does not contain the element.
Exception: This method throws:
- ClassCastException: if the type of the specified element is incompatible with this list.
- NullPointerException: if the specified element is null and this list does not permit null elements.
Below are the examples to illustrate the lastIndexOf() method.
Example 1:
// Java program to demonstrate lastIndexOf()// method for AbstractSequentialList  import java.util.*;  public class GFG {    public static void main(String[] args)    {          // Creating object of AbstractSequentialList        AbstractSequentialList<Integer>            arrlist1 = new LinkedList<Integer>();          // Populating arrlist1        arrlist1.add(10);        arrlist1.add(20);        arrlist1.add(30);        arrlist1.add(40);        arrlist1.add(50);          // print arrlist1        System.out.println("AbstractSequentialList: "                           + arrlist1);          // getting the index of element 30        // using lastIndexOf() method        int index = arrlist1.lastIndexOf(30);          // print the index        System.out.println("Last Index of 30: "                           + index);    }} |
Output:
AbstractSequentialList: [10, 20, 30, 40, 50] Last Index of 30: 2
Example 2:
// Java program to demonstrate lastIndexOf()// method for AbstractSequentialList  import java.util.*;  public class GFG1 {    public static void main(String[] args)    {        // Creating object of AbstractSequentialList        AbstractSequentialList<Integer>            arrlist1 = new LinkedList<Integer>();          // Populating arrlist1        arrlist1.add(10);        arrlist1.add(20);        arrlist1.add(30);        arrlist1.add(40);        arrlist1.add(50);          // print arrlist1        System.out.println("LinkedListlist: "                           + arrlist1);          // getting the index of element 100        // using lastIndexOf() method        int index = arrlist1.lastIndexOf(100);          // print the index        System.out.println("Last Index of 100: "                           + index);    }} |
Output:
LinkedListlist: [10, 20, 30, 40, 50] Last Index of 100: -1
