What is the Stack.insertElementAt() method in Java?

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 insertElementAt() method of the Stack class can be used to add an element at the specific index of the Stack object. The index of the elements present at and after the passed index will be shifted upward (increased by 1).

Syntax

public void insertElementAt(E obj,int index)

Parameters

This method takes two parameters:

The element to be added to the Stack object.
The index at which the new element is to be added. The index should be positive and less than or equal to the size of the Stack, as shown below. Otherwise, ArrayIndexOutOfBoundsException will be thrown.

index >= 0 && index <= size()

Return value

insertElementAt() doesn’t return a value.

Code

The code below demonstrates the use of the Stack.insertElementAt() method:

import java.util.Stack;
class InsertElementAt {
    public static void main( String args[] ) {
        // Creating Stack
        Stack<Integer> stack = new Stack<>();
        // add elememts 
        stack.push(10);
        stack.push(30);
        stack.push(50);
        System.out.println("The stack is: " + stack); // [10,30,50]
        stack.insertElementAt(20, 1); // [10,20,30,50]
        System.out.println("\nAfter calling insertElementAt(20,1). The stack is: " + stack);
        stack.insertElementAt(40, 3);   // [10,20,30,40,50]
        System.out.println("\nAfter calling insertElementAt(40,3). The stack is: " + stack);
    }
}

What is the Stack.insertElementAt() method in Java?

Syntax

Parameters

Return value

Code

Explanation