从测试文件向类中的数组添加对象？

Question

Unsure on how i'm supposed to add to an array, i've been asked to fill the array from a test file but define it in class Patient. Any ideas?

   public class Patient
   {
   private String name;
   private int id;
   private int current = 1;
   public Patient(String name, int id)
   {
      this.name = name;
      this.id = id;
      Patient[] patient = new Patient[100];
      String[] Observations;
      System.out.print(patient[0]);
   }
  public String addPatient(String name,int id)
  {
     Patient[current-1] = new Patient(name,id);
  }
} 

// extract from class  PatientRecordSystem
public void addPatient()
{
  String name = "James";
  int id = 10122;
  Patient patient = new Patient(name, id);
}

Answer 1

Your problem is that you are defining that list (or array) to hold Patient objects within the constructor of your Patient class.

That is simply wrong on many levels. First of all - one "Patient" should be exactly that - the representation of a single patient . When you go to the doctor and become a patient ... are you asked to know about 100 other patients around?! Then: that array that you define in the constructor ... just lives during the execution of the constructor. It simply goes away as soon as a call

Patient newPatient = new Patient( ... ) 

returns.

In other words: you want to think of another class that is responsible for "managing" multiple patients. And then you create "patient objects"; and tell the manager about them. And that "manager" is then using an array (or better some more dynamic List) in order to keep track of "managed" patients.

Answer 2

Whatever Andrew said is correct , just making it easy for you. Use below code

  public class Patient
   {
   private String name;
   private int id;
   private int current = 1;
   private Patient[] patient = new Patient[100];
   public Patient(String name, int id)
   {
      this.name = name;
      this.id = id;

      String[] Observations;
      System.out.print(patient[0]);
   }
  public String addPatient(String name,int id)
  {
     patient[current-1] = new Patient(name,id);
  }
} 

// extract from class  PatientRecordSystem
public void addPatient()
{
  String name = "James";
  int id = 10122;
  Patient patient = new Patient(name, id);
}

Answer 3

First you need to declare the array.

You can do something like:

Patient[] patients = new Patient[100];

if you know the size of the array.

If you want to build a dynamic array, because you don't know how many elements you are going to have, you can do something like that.

List<Patient> patients = new ArrayList<Patient>();

Then you can assign values to the array:

If you have declared a fixed array you can do something like that:

patients[0] = new Patient(name, id);

On the other hand, if you have declared a dynamic array, the code would look like:

patients.add(new Patient(name, id));