The Java.util.Stack.insertElementAt(element, index) method is used to insert a particular element at the specified index of the Stack. Both the element and the position is passed as the parameters. If an element is inserted at a specified index, then all the elements are pushed upward by one and hence the capacity is increased, creating a space for the new element.
Syntax:
Stack.insertElementAt()
Parameters: The method accepts two parameters:
- element: This is element required to be inserted into the Stack.
- index: This is of integer type and refers to the position where the new element is to be inserted.
Return Value: The method does not return anything.
Exception: The method throws ArrayIndexOutOfBoundsException if the index is an invalid number.
Below programs illustrate the Java.util.Stack.insertElementAt() method:
Program 1: Adding String elements into the Stack.
// Java code to illustrate insertElementAt() 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 into the Stack
stack.add("Welcome");
stack.add("To");
stack.add("Geeks");
stack.add(" 4 ");
stack.add("Geeks");
// Displaying the Stack
System.out.println("Stack: " + stack);
// Inserting element at 3rd position
stack.insertElementAt("Hello", 2 );
// Inserting element at last position
stack.insertElementAt("World", 6 );
// Displaying the final Stack
System.out.println("The final Stack is "
+ stack);
}
} |
Stack: [Welcome, To, Geeks, 4, Geeks] The final Stack is [Welcome, To, Hello, Geeks, 4, Geeks, World]
Program 2: Adding Integer elements into the Stack.
// Java code to illustrate insertElementAt() 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 into the Stack
stack.add( 10 );
stack.add( 20 );
stack.add( 30 );
stack.add( 40 );
stack.add( 50 );
// Displaying the Stack
System.out.println("Stack: " + stack);
// Inserting element at 1st position
stack.insertElementAt( 100 , 0 );
// Inserting element at fifth position
stack.insertElementAt( 200 , 4 );
// Displaying the final Stack
System.out.println("The final Stack is "
+ stack);
}
} |
Stack: [10, 20, 30, 40, 50] The final Stack is [100, 10, 20, 30, 200, 40, 50]