Practice Java College

Question

I am starting Java and also new to this site. I learn about arrays and methods, and unfortunately I'm stuck. The question is:

The hospital has room for 150 patients. Each room has space for 3 patients.
The hospital pays the patient $ 150 to stay. If 3 patients are occupied in each room, the hospital charges an additional $ 50. Tell the user the number of patients and show the total number of patients, the total number of all fees.

In my opinion, I would like to create a parallel array from the number of rooms and another array of the number of patients for each room.

The problem is this: every time the program asks for the following. Enter # patients in room 0 Enter # patients in room 0 Enter # patients in room 0 Instead: Enter # patients for number 1 Enter # patients for number 2 Enter # patients for number 3

So, I think this is a logical mistake, because roomNumbers [i] is not updated to room 1, room2, etc., it asks for number 0 all the time, please, every advice is welcome, as I am just starting with this new course for the next semester. Does my logic really make sense? Thank you very much.

import javax.swing.JOptionPane; public class Pingo { public static void main(String[] args) { final int MAXROOMS=50; int[] roomNumbers = new int[MAXROOMS]; int [] patientQuantity = new int [roomNumbers.length]; int numPatients=getNumberOfPatients(roomNumbers,patientQuantity); } public static int getNumberOfPatients(int[] roomNumbers, int []patientQuantity){ int numPatients=0; for(int i=0; i<patientQuantity.length; i++){ numPatients=Integer.parseInt(JOptionPane.showInputDialog("Enter amount of Patients for room:" + roomNumbers[i] )); patientQuantity[i]=numPatients; } return numPatients; } } 

Answer 1

The problem is here:

 int[] roomNumbers = new int[MAXROOMS]; 

You declare an array and initialize it. The problem is that the values ​​in the array are zero. This is due to the fact that when distributing an array using new values ​​of the elements will be initialized by default in accordance with the type of the base array:

• Numeric types have an initial default value of zero.
• The bool type has an initial default value of false .
• Link types (classes and array types) have an initial default value of null .

There are two simple solutions here:

• Set initial values ​​for each element of the array; for example using a loop.
• Do not use an array to store room numbers; for example, do some simple arithmetic and use your index variable ( i ) to calculate the room number. (Think about it...)