I want to create add an edit functionality (`public void EditPatientData()`) to edit the patients surname, firstname,
dateOfBirth, Length and weight. In other words I want to be able to edit the Patient's in the system Id, Surname, firtstname etc.

```
     import java.text.DecimalFormat;
     import java.time.LocalDate;
     import java.time.Period;
     import java.util.ArrayList;
     import java.util.Collection;
     import java.util.Iterator;
     import java.util.Scanner;

     public class Patient {
        private static final int RETURN = 0;
        private static final int SURNAME = 1;
        private static final int FIRSTNAME = 2;
        private static final int DATEOFBIRTH = 3;
        private static final int LENGTH = 4;
        private static final int WEIGHT = 5;
        private static final int EDIT = 6;

        private int id;
        private String surname;
        private String firstName;
        private LocalDate dateOfBirth;
        private double length;
        private double weight;

        ////////////////////////////////////////////////////////////////////////////////
        ////////////////////////////////////////////////////////////////////////////////

        public int getId() {
        return id;
        }

        public String getSurname() {
          return surname;
        }

        public String getFirstName() {
          return firstName;
        }

        public LocalDate getDateOfBirth() {
          return dateOfBirth;
        }

        public double getLength() {
          return length;
        }

        public double getWeight() {
          return weight;
        }
// Method to calculate the age of a patient

           public int calcAge(LocalDate dateOfBirth) {
        //Code gets current date
           LocalDate curDate = LocalDate.now();
        //If else statement that checks if both dates are not null/
        if ((dateOfBirth != null) && (curDate != null)) {
         /*if dates are both not null the code will take the birthdate and currentdate and
         calculate the difference the code will calculate the age in years */
         return Period.between(dateOfBirth, curDate).getYears();
      } else {
         //if one or both dates are null the code will return 0
         return 0;
      }
    }

//this code formats the double in 2 decimals so it looks cleaner

     private static final DecimalFormat df = new DecimalFormat("0.00");

     //this code calculates the BMI of the patient
     public String calcBMI(double weight, double length) {
       return df.format(weight / (length * length));
     }

// Constructor

     Patient(int id, String surname, String firstName, LocalDate dateOfBirth, double weight, 
      double length) {
      this.id = id;
      this.surname = surname;
      this.firstName = firstName;
      this.dateOfBirth = dateOfBirth;
      this.weight = weight;
      this.length = length;
      }

// Display patient data.

     public void viewData() {
      System.out.format("===== Patient id=%d ==============================\n", id);
      System.out.format("%-17s %s\n", "Surname:", surname);
      System.out.format("%-17s %s\n", "firstName:", firstName);
      System.out.format("%-17s %s\n", "Date of birth:", dateOfBirth);
      System.out.format("%-17s %s\n", "Age:", calcAge(dateOfBirth));
      System.out.format("%-17s %s\n", "Weight in KG:", weight);
      System.out.format("%-17s %s\n", "Length in M:", length);
      System.out.format("%-17s %s\n", "The Patients BMI:", calcBMI(weight, length));
      }

// Shorthand for a Patient's full name1

     public String fullName() {
      return String.format("%s %s [%s]", firstName, surname, dateOfBirth.toString(), 
     calcAge(dateOfBirth), weight, length, calcBMI(weight, length));
     }

 //Edit patient data.
     public void EditPatientData() {

     }
    }

```