Java Vector lastIndexOf() Method

The lastIndexOf() Java Vector class method is used to get the index of the last occurrence of the specified element in the vector. There are two different types of Java lastIndexOf() method which can be differentiated depending on its parameter. These are:

Java Vector lastIndexOf(Object o) Method
Java Vector lastIndexOf(Object o, int index) Method

lastIndexOf(Object o) Method:

It returns the index of the last occurrence of the specified element in this vector. If the element is not found, it returns -1.

lastIndexOf(Object o, int index> c) Method:

This method is used to get the index of the last occurrence of the specified element in this vector. It starts searching for an element in the backward direction from the specified index. If the element is not found, it returns -1.

Syntax

Following is the declaration of lastIndexOf() method:

public int lastIndexOf(Object obj)
public int lastIndexOf(Object obj, int index)

Parameter

Parameter	Description	Required/Optional
index	It is an index where to start searching for an element in the backward direction.	Required
obj	It is an element to search for.	Required

Return

The lastIndexOf() method returns the index of the last occurrence of the specified element in this vector or returns -1 if the vector does not contain the element.

Exceptions

IndexOutOfBoundsException- This method has thrown an exception if the index of an array is out of range i.e. (index >= size()).

Compatibility Version

Java 1.2 and above

Example 1

import java.util.*;
public class VectorLastIndexOfExample1 {  
	public static void main(String arg[]) {	
		//Create an empty Vector      
		Vector < Integer > in = new Vector < > ();
		//Add elements in the vector
		in.add(100);
		in.add(200);
		in.add(300);
		in.add(100);
		in.add(400);
            //Obtain an index of last occurrence of the specified element
		System.out.println("Index of element is: " +in.lastIndexOf(100));
	      }            
}

Test it Now

Output:

Index of element is: 3

Example 2

import java.util.*;
public class VectorLastIndexOfExample2 {  
	public static void main(String arg[]) {	
		//Create an empty vector   
	      Vector<String> vec = new Vector<>(4); 
	      //Add elements in the vector	      
	      vec.add("Java");
	      vec.add("JavaScript");
	      vec.add("Android");
	      vec.add("Python");
            //Obtain an index of the last occurrence of the specified element
		System.out.println("Index of element is: " +vec.lastIndexOf("C"));
		System.out.println("The element is not found.");
	      }            
}

Test it Now

Output:

Index of element is: -1
The element is not found.

Example 3

import java.util.*;
public class VectorLastIndexOfExample3 {  
	public static void main(String arg[]) {	
		//Create a first empty vector   
	      Vector<String> vec = new Vector<>(4); 
	      //Add elements in the first vector	      
	      vec.add("Facebook");
	      vec.add("Whatsapp");
	      vec.add("Twitter");
	      vec.add("Instagram");
	      vec.add("Skype");
            //This would start searching of element in the backward direction from index -2
		System.out.println("Index of element is found at: " +vec.lastIndexOf("Skype", 6));		
	}            
}

Test it Now

Output:

Exception in thread "main" java.lang.IndexOutOfBoundsException: 6 >= 5
	at java.base/java.util.Vector.lastIndexOf(Vector.java:469)
	at myPackage.VectorLastIndexOfExample3.main(VectorLastIndexOfExample3.java:14)

Example 4

import java.util.*;
public class VectorLastIndexOfExample4 {  
	public static void main(String arg[]) {	
		//Create an empty Vector      
		Vector < Integer > in = new Vector < > ();
		//Add elements in the vector
		in.add(101);
		in.add(201);
		in.add(301);
		in.add(401);
		in.add(501);
            //This would start searching of element in the backward direction from index 3
		System.out.println("Index of element is found at: " +in.lastIndexOf(201, 3));		
	}            
}

Test it Now

Output: