Create several new objects within a for-loop in Java

Question

I want to create several objects from a class in a for loop. but I don't know how to code it. What I have written creates a new object but it overwrites the previous object.

package assginment1_version4;

import java.util.*;

public class Client {

public static void main (String[] args) {
    System.out.println ("this is a bill database");
    System.out.println ("add a user?(Y/N)");

    Scanner input = new Scanner(System.in);
    String answer = input.nextLine ();
    ArrayList ary = new ArrayList ();

    for (int i=1 ; i < 100; i++) {
        if (answer.equalsIgnoreCase("y")) {
            Bill bill1 = new Bill();
            System.out.println("user first name:");
            bill1.setFname (input.nextLine());
            System.out.println("user Last name:");
            bill1.setLname (input.nextLine());
            System.out.println ("add a user?(Y/N)");
            answer = input.nextLine ();
        } else if (answer.equalsIgnoreCase ("n")) {
            if (Bill.getBillCounter () == 0) {
                System.out.println ("the Database is empty");
                break;
            } else {
                System.out.println ("Number of Users:  "
                        + Bill.getBillCounter ());
                break;
            }
        } else {
            while (!answer.equalsIgnoreCase ("n")
                    && !answer.equalsIgnoreCase ("y")) {
                System.out.println ("add a user?(Y/N)");
                answer = input.nextLine ();
                }
            }
        }
    }
}

please help me to complete this code.

Answer 1

This is the Bill class.....

package assginment1_version2;

public class Bill {

/**
 *  Attributes of a bill
 */
private String firstName;
private String lastName;
private int paymentDeadline;
private int paymentCode;
private int billCode;

/**
* Attribute of Bill Class
*/

      private static int BillCounter=0;

/**
 *  Methods of Bill class
 * @return number of users
 */
/*public static int getBillCounter(){
    return BillCounter;
}*/


/**
 * Class Constructor
 * @param Fname is the first name of user
 * @param Lname is the last name of user
 * @param Pdeadline is the deadline of paying the bill
 * @param Pcode introduces the payment uniquely 
 * @param Bcode introduces the bill uniquely
 */
    public Bill (){
        BillCounter++;
    }

/**
 *  FirstName methods 
 *  method to set FirstName
 * @param n is the input of setname method as a user name
 */
public void setFname (String n){
    firstName=n;
}
// method to get FirstName
public String getFname (){
    return firstName;
}


/**
 *  LastName methods
 *  method to set LastName
 */
public void setLname (String m){
    lastName=m;
}
// method to get LastName 
public String getLname(){
    return lastName;
}


/**
 * PaymentDeadline methods
 * method to set PaymentDeadline     
 */
public void setPaymentDeadline(int m){
    paymentDeadline= m;
}
//method to get PaymentDeadline
public int getPaymentDeadline(){
    return paymentDeadline;
}

/*
 * PaymentCode methods
 * Method to set PaymentCode
 */
public void setPaymentCode (int m){
    paymentCode=m;
}
//method to get PaymentCode
public int getPaymentCode(){
    return paymentCode;
}

/*
 * Methods of BillCode
 * method to set BillCode 
 */
public void setBcode(int Bcode){
    billCode=Bcode;
}
//method to get BillCode
public int getBcode(){
    return billCode;
}
}

Answer 2

You're overriding them because you create a new Bill on each loop and never save them off anywhere. I believe you want to add them to your ArrayList:

First, you should add a type to your ArrayList:

ArrayList<Bill> ary = new ArrayList<Bill>();

Then, before you get the input from the user on whether or not to add a new Bill, you should add the current one to this list:

...
System.out.println("user Last name:");
bill1.setLname(input.nextLine());
ary.add(bill1);
...

Answer 3

You haven't used the ArrayList, you need to add the Bill's objects at the end of the for loop.

ary.add(bill1);

and add a type to your ArrayList

ArrayList<Bill> ary = new ArrayList<Bill>();