Simple Ordering System (Console)

import java.util.*;
 
public class cart
{
        //To publicly access the quantity as it updates every time you wish to buy again
	public static int total_quantity=0;
	//I have declared 4 products here 
	public static String[] products = {null, "1.) Quarter-Pounder Burger 50.00",
	 											"2.) One-Percenter (2-Stacks of Quarter Pounder Patty) 99.00",
	 											"3.) Tombstone Piledriver (3 Stacks of Quarter Pounder Patty) 150.00",
	 											"4.) God's Last Gift (Tombstone Burger with 100g of Carolina Reaper) 200.00"};
	//Prices in accordance of their elements
	public static int[] product_price ={0,50,99,150,200};
	//This is the cart for the check-out of all order you have
	public static int[] final_qty=new int[5];
 
	public static void main(String[] args)
	{
		Scanner s = new Scanner(System.in);
		int choose, quantity;
		int p1=0;
		int p2=0;
		int p3=0;
		int p4=0;
		char decision;
		System.out.println("Welcome to Burger TK, please choose any of the menu there..");
		do
		{
 
			for(int i = 0; i < products.length; i++)
			{
				if(products[i] != null)
				System.out.println(products[i]);
			}
 
			System.out.print("Choose any item: ");
			choose=s.nextInt();
 
			System.out.print("How many pieces? ");
			quantity=s.nextInt();
 
			switch(choose)
			{
				case 1:
				p1 += quantity;
				final_qty[1]=p1;
				break;
 
				case 2:
				p2 += quantity;
				final_qty[2]=p2;
				break;
 
				case 3: 
				p3 += quantity;
				final_qty[3]=p3;
				break;
 
				case 4: 
				p4 += quantity;
				final_qty[4]=p4;
				break;
			}
			System.out.print("Would you like to order again? Y/N / y/n: ");	
			decision=s.next().charAt(0);
		}while(decision != 'n' && decision != 'N');
 
		System.out.println("==Final Cart==");
		System.out.println("\t\\Item\t\\Qty\t\\Total");
		int sum=0;
		for(int i=0; i < final_qty.length; i++)
		{
			if(final_qty[i] != 0)
			{
				System.out.println(products[i]+"\\"+final_qty[i]+"\\"+final_qty[i]*product_price[i]);
				sum = sum + final_qty[i]*product_price[i];
			}
		}
		System.out.println("Total Purchased items: "+(p1+p2+p3+p4));
		System.out.println("Total Purchase: "+sum);
		int payment=0;
		do
		{
		System.out.print("Enter Payment: ");
		payment=s.nextInt();
		}while(sum > payment);
		System.out.println("Thank you for buying! here's your change: "+(payment-sum));
	}	
 
}