Two instances of a class: only sort 1

Question

I have a basic class that has four attributes (Patient). In Main() I have reserved the memory for the array and before I actually create the instance, I ask the user for the account number to ensure it doesn't already exist within the array. So BinarySearch requires it to be sorted but as soon as I sort it the ability to do the for loop is lost.

//Variables
int intMaxNum = 5; //set max number of patients to 5
int intInputValue;
int intResult;
string strTempName;
int intTempAge;
double dblTempTotal;

Patient[] objectPatient = new Patient[intMaxNum]; //create an array of references

for (int x = 0; x < objectPatient.Length; ++x)
{
   //attempt to create a 'shadow' class to search through and keep integrity of main class (objectPatient)
   Patient[] tempobjectPatient = new Patient[intMaxNum];
   tempobjectPatient = objectPatient;
   if (x > 0)
   {

      Console.Write("\n***Next Patient***");

      Array.Sort(tempobjectPatient); //this will sort both objects even though I send the temporary class only - interface impact I'm sure
   }

   //ask for the Patient Account number
   Console.Write("\nEnter Patient Account Number: ");
   ReadTheAccountNumber:
   intInputValue = Convert.ToInt32(Console.ReadLine());
   //create temporary class for comparison
   Patient SeekPatient = new Patient();
   SeekPatient.PatientNumber=intInputValue; // reset the default info with the input Pateint Account Number

   //verify the Patient Account number doesn't already exist
   intResult = Array.BinarySearch(tempobjectPatient, SeekPatient);
   //intResult = Array.BinarySearch(objectPatient, SeekPatient);

   //if (objectPatient.Equals(SeekPatient)) //Can not get the .Equals to work at all...
   if (intResult >= 0)
   {
      Console.Write("\nSorry, Patient Account Number {0} is a duplicate.", intInputValue);
      Console.Write("\nPlease re-enter the Patient Account Number: ");
      goto ReadTheAccountNumber;
   }
   else //no match found, get the rest of the data and create the object
   {
      if (x > 0) { Console.Write("***Patient Account Number unique and accepted***\n"); } //looks silly to display this if entering the first record
      Console.Write("Enter the Patient Name: ");
      strTempName = Console.ReadLine();
      Console.Write("Enter the Patient Age: ");
      intTempAge = Convert.ToInt32(Console.ReadLine());
      Console.Write("Enter the total annual Patient amount due: ");
      dblTempTotal = Convert.ToDouble(Console.ReadLine());
      objectPatient[x] = new Patient(intInputValue, strTempName, intTempAge, dblTempTotal);
   }
}

Here is the class:

class Patient : IComparable
{
    //Data fields
    private int patientNumber;
    private string patientName;
    private int patientAge;
    private double patientAmountDue;

    //Constructors
    public Patient(): this(9,"ZZZ",0,0.00)
    {
    }
    public Patient(int _patientNumber, string _patientName, int _patientAge, double _patientAmountDue)
    {
       PatientNumber = _patientNumber;
       PatientName = _patientName;
       PatientAge = _patientAge;
       PatientAmountDue = _patientAmountDue;
    }
    //Properties
    public int PatientNumber
    { 
       get { return patientNumber; }
       set { patientNumber = value; }
    }
    public string PatientName
    {
       get { return patientName; }
       set { patientName = value; }
    }
    public int PatientAge
    {
       get { return patientAge; }
       set { patientAge = value; }
    }
    public double PatientAmountDue
    {
       get { return patientAmountDue; }
       set { patientAmountDue = value; }
    }

    //Interfaces
    int IComparable.CompareTo(Object o)
    {
       int returnVal; //temporary value container

       Patient temp = (Patient)o; //create temp instance of the class
       if (this.PatientNumber > temp.PatientNumber)
          returnVal = 1;
       else
          if (this.PatientNumber < temp.PatientNumber)
             returnVal = -1;
          else
             returnVal = 0; //exact match
       return returnVal;
    }
}

Answer 1

This

Patient[] tempobjectPatient = new Patient[intMaxNum];

creates a new array and assigns it to tempobjectPatient. But this new array is never used, because here

tempobjectPatient = objectPatient;

you immediately assign the old one to tempobjectPatient. So after this, you don't have two array instances. Both tempobjectPatient and objectPatient refer to the same instance.

You probably want:

Patient[] tempobjectPatient = (Patient[])objectPatient.Clone();