Stack push() Method in Java
Last Updated :
10 Jun, 2022
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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 Code to illustrate push() Method
import java.util.*;
// Main class
public 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 code to illustrate push() method
import 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]
