What is the Stack.lastIndexOf method in Java?

Overview

The Stack class is a Last-In-First-Out (LIFO)The element inserted first is processed last and the element inserted last is processed first. stack of objects.

The lastIndexOf method is used to get the index of the last occurrence of the specified element in the Stack object.

Syntax

import java.util.Stack;
class LastIndexOfExample {
    public static void main( String args[] ) {
      Stack<String> stack = new Stack<>();
      stack.push("1");
      stack.push("2");
      stack.push("1");
      System.out.println("The stack is " + stack);
      System.out.println("Last Index of element '1' is : " + stack.lastIndexOf("1"));
      System.out.println("Last Index of element '2' is : " + stack.lastIndexOf("2"));
      System.out.println("Last Index of element '3' is : " + stack.lastIndexOf("3"));
    }
}

Explanation

In the code above:

In line 1, we import the Stack class.
In line 4, we create a new object of Stack with the name stack.
From lines 5 to 7, we use the push method of the stack object to add three elements ("1","2","3") to the stack.
In line 10, we use the lastIndexOf method of the stack object to get the index of the last occurrence of the element "1". The element "1" is present at two indices, 0 and 2. We get 2 as a result since that is the last occurrence.
In line 11, we use the lastIndexOf method of the stack object to get the index of the last occurrence of the element "2". The element "2" is only present at index 1, so it is returned.
In line 12, we use the lastIndexOf method of the stack object to get the index of the last occurrence of the element "3". The element "3" is not present in the stack, so the method returns -1.

What is the Stack.lastIndexOf method in Java?

Overview

Syntax

Parameters

Return value

Code

Explanation