STACK JAVA ARR

/*
    program for stack implementation in java using array
 */
package javaapp;

import java.io.*;
import java.util.Scanner;
class stax {

    private int[] stk;
    private int top;

    // constructor for stax class
    public stax() {

        this.stk = new int[20];
        this.top = -1;
    }

    public void push(int element) {
        top++;

        if (top == 20) {
            System.out.println("Stackfull!!");
            return;
        } else {
            stk[top] = element;
            System.out.println("Item pushed");
        }
    }

    public int pop() {

        if (top == -1) {
            System.out.println("Stackempty!!");
            return 99999;       // assuming that 99999 never appears in the stack
        } else {
            int element = stk[top];
            top--;
            return element;
        }
    }

    //display stack contents
    void display() {
        int i;
        for (i = 0; i <= top; i++) {
            System.out.println("" + stk[i]);
        }
    }
}

public class stackimpl {

    public static void main(String args[]) {
        int element, cont, choice;
        cont = 1;
        stax s1 = new stax();
        Scanner sc = new Scanner(System.in);

        do {
            System.out.println("THE FOLLOWING CHOICES ARE AVAILIABLE : ");
            System.out.println("1.PUSH AN ELEMENT");
            System.out.println("2.POP AN ELEMENT");
            System.out.println("3.VIEW STACK CONTENTS");
            System.out.println("ENTER YOUR CHOICE : ");
            choice = sc.nextInt();

            switch (choice) {
                case 1:
                    System.out.println("ENTER THE ELEMENT TO BE PUSHED : ");
                    element = sc.nextInt();
                    s1.push(element);
                    break;

                case 2:
                    element = s1.pop();
                    if (element != 99999) {
                        System.out.println("THE ELEMENT POPPED  IS : " + element);
                    }
                    break;

                case 3:
                    System.out.println("THE ELEMENTS OF STACK ARE : ");
                    s1.display();
                    break;
            }
            System.out.println("DO YOU WANT TO CONTINUE (1/0): ");
            cont = sc.nextInt();

        } while (cont == 1);
        return;
    }

}