Stack lastIndexOf() method in Java with Example

The Java.util.Stack.lastIndexOf(Object element) method is used to check and find the occurrence of a particular element in the Stack. If the element is present in the Stack then the lastIndexOf() method returns the index of last occurrence of the element otherwise it returns -1. This method is used to find the last occurrence of a particular element in a Stack.

Syntax:

Stack.lastIndexOf(Object element)

Parameters: The parameter element is of type Stack. It refers to the element whose last occurrence is required to be checked.

Return Value: The method returns the position of the last occurrence of the element in the Stack. If the element is not present in the Stack then the method returns -1. The returned value is of integer type.

Below programs illustrate the Java.util.Stack.lastIndexOf() method:

Program 1:

// Java code to illustrate lastIndexOf()
import java.util.*;

public class StackDemo {
    public static void main(String args[])
    {

        // Creating an empty Stack
        Stack<String> stack = new Stack<String>();

        // Use add() method to add elements in the Stack
        stack.add("Geeks");
        stack.add("for");
        stack.add("Geeks");
        stack.add("10");
        stack.add("20");

        // Displaying the Stack
        System.out.println("Stack: " + stack);

        // The last position of an element is returned
        System.out.println("Last occurrence of Geeks is at index: "
                           + stack.lastIndexOf("Geeks"));
        System.out.println("Last occurrence of 10 is at index: "
                           + stack.lastIndexOf("10"));
    }
}

Output:

Stack: [Geeks, for, Geeks, 10, 20]
Last occurrence of Geeks is at index: 2
Last occurrence of 10 is at index: 3

Program 2:

// Java code to illustrate lastIndexOf()
import java.util.*;

public class StackDemo {
    public static void main(String args[])
    {

        // Creating an empty Stack
        Stack<Integer> stack = new Stack<Integer>();

        // Use add() method to add elements in the Stack
        stack.add(10);
        stack.add(22);
        stack.add(3);
        stack.add(10);
        stack.add(20);

        // Displaying the Stack
        System.out.println("Stack: " + stack);

        // The last position of an element is returned
        System.out.println("Last occurrence of 10 is at index: "
                           + stack.lastIndexOf(10));
        System.out.println("Last occurrence of 20 is at index: "
                           + stack.lastIndexOf(20));
    }
}

Output:

Stack: [10, 22, 3, 10, 20]
Last occurrence of 10 is at index: 3
Last occurrence of 20 is at index: 4