The Java.util.Stack.firstElement() method in Java is used to retrieve or fetch the first element of the Stack. It returns the element present at the 0th index of the Stack
Syntax:
Stack.firstElement()
Parameters: The method does not take any parameter.
Return Value: The method returns the first element present in the Stack.
Below programs illustrate the Java.util.Stack.firstElement() method:
Program 1:
// Java code to illustrate firstElement() 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);
// Displaying the first element
System.out.println( "The first element is: "
+ stack.firstElement());
}
} |
Output:
Stack: [Welcome, To, Geeks, 4, Geeks] The first element is: Welcome
Program 2:
// Java code to illustrate firstElement() 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( 15 );
stack.add( 30 );
stack.add( 20 );
stack.add( 5 );
// Displaying the Stack
System.out.println( "Stack: " + stack);
// Displaying the first element
System.out.println( "The first element is: "
+ stack.firstElement());
}
} |
Output:
Stack: [10, 15, 30, 20, 5] The first element is: 10