Java.util.Stack.push(E element) method is used to push an element into the Stack. The element gets pushed onto the top of the Stack.
Syntax:
STACK.push(E element)
Parameters: The method accepts one parameter element of type Stack and refers to the element to be pushed into the stack.
Return Value: The method returns the argument passed. It also accepts the null value unlike ArrayDeque.push() which throws java.lang.NullPointerException on doing the same.
Below programs illustrate the Java.util.Stack.push() method:
Program 1: Adding String elements into the Stack.
Java
// Java Code to illustrate push() Methodimport java.util.*;// Main classpublic class StackDemo { // Main driver method public static void main(String args[]) { // Creating an empty Stack Stack& lt; String& gt; STACK = new Stack& lt; String& gt; (); // Adding elements into the stack // using push() method STACK.push(" Welcome & quot;); STACK.push(" To & quot;); STACK.push(" Geeks & quot;); STACK.push(" For & quot;); STACK.push(" Geeks & quot;); // Displaying the Stack System.out.println(" Initial Stack : " + STACK); // Pushing elements into the stack STACK.push(" Hello & quot;); STACK.push(" World & quot;); // Displaying the final Stack System.out.println(" Final Stack : " + STACK); }} |
Output:
Initial Stack: [Welcome, To, Geeks, For, Geeks] Final Stack: [Welcome, To, Geeks, For, Geeks, Hello, World]
Program 2: Adding Integer elements into the Stack.
Java
// Java code to illustrate push() methodimport java.util.*;public class StackDemo { public static void main(String args[]) { // Creating an empty Stack Stack<Integer> STACK = new Stack<Integer>(); // Use push() to add elements into the Stack STACK.push(10); STACK.push(15); STACK.push(30); STACK.push(20); STACK.push(5); STACK.push(null); // Displaying the Stack System.out.println("Initial Stack: " + STACK); // Pushing elements into the Stack STACK.push(1254); STACK.push(4521); // Displaying the final Stack System.out.println("Final Stack: " + STACK); }} |
Output:
Initial Stack: [10, 15, 30, 20, 5] Final Stack: [10, 15, 30, 20, 5, 1254, 4521]
