Java Setters not working as intended on Array object

Question

I´m quite new to Java and want to write code that creates objects, shows (prints) and edits them.

1. I wrote a class:

   public class Person {

   protected String firstName;
   protected String lastName;
   protected String fullName;
   protected Date dob;
   protected int id;
   
   public Person(String firstName, String lastName, Date dob, int id) {
       this.firstName = firstName;
       this.lastName = lastName;
       this.dob = dob;
       this.fullName = this.firstName + " " + this.lastName;
       this.id = id;
   
   }
   
   public String getFirstName() {return this.firstName;}
   public String getLastName() {return this.lastName;}
   public String getFullName() {
       return this.fullName;
   }
   public Date getDob() {
       return this.dob;
   }
   public int getId() {
       return this.id;
   }
   
   public void printAll() {
       System.out.println(this.fullName);
       System.out.println(this.dob);
       System.out.println(this.id);
   }
   
   public void setFirstName(String firstName) {
       this.firstName = firstName;
   }
   
   public void setLastName(String lastName) {
       this.lastName = lastName;
   }
   
   public void setDob(Date dob) {
       this.dob = dob;
   }
   
   public boolean containsFullName(String fullName) {
       if (this.fullName.equalsIgnoreCase(fullName)) {
           return true;
       } else {
           return false;
       }
   }
   public boolean containsId(int id) {
       if (this.id == id) {
           return true;
       } else {
           return false;
       }
   }
   

   }

2. I created an Array of Person in Main Class. (100 objects).

public class Main {

final static int MAX_NUMBER_PERSONS = 100;
static Person[] person = new Person[MAX_NUMBER_PERSONS];
static int mainCount = 0;
static Scanner scan = new Scanner(System.in);

3. upon corresponding command the user may create an object within this array (It´s german, but basically its reading first name, last name and date of birth). mainCount is used to keep track on which position within the array the object is created:

   public static void createPerson() throws ParseException {

   Scanner scan = new Scanner(System.in);
   
   // Namen erfassen:
   System.out.println("Bitte den Vornamen der Person eingeben:");
   String firstName = scan.nextLine();
   System.out.println("Bitte den Nachnamen der Person eingeben:");
   String lastName = scan.nextLine();
   String fullName = firstName + " " + lastName;
   
   // DOB erfassen:
   System.out.println("Bitte Geburtsdatum von " + fullName + " eingeben (TT/MM/JJJJ):");
   String dob = scan.next();
   Date dobDate = new SimpleDateFormat("dd/MM/yyyy").parse(dob);
   
   int id = mainCount;
   
   person[mainCount] = new Person(firstName, lastName, dobDate, id);
   ++mainCount;
   System.out.println("Du hast Person Nummer " + mainCount + " erstellt");
   

   }

4. NOW THE ACTUAL ISSUE: calling the following method the user should be able to edit the desired object within the array by using user input and setters:

   public static void editPerson() throws ParseException { Scanner scan = new Scanner(System.in); System.out.println("Bitte die ID der zu bearbeitenden Person eingeben (zu finden über )..."); int id = scan.nextInt(); scan.nextLine(); searchByIdReturn(id).printAll();

   System.out.println("Diese Person bearbeiten? Tippe <ja>, sonst zurück zum Menü.");
   if(scan.next().equalsIgnoreCase("ja")) {
       scan.nextLine();
       System.out.println("Vorname eingeben...");
       String firstName = scan.nextLine();
       searchByIdReturn(id).setFirstName(firstName);
       System.out.println("Nachname eingeben...");
       String lastName = scan.nextLine();
       searchByIdReturn(id).setLastName(lastName);
       System.out.println("Bitte Geburtsdatum eingeben (TT/MM/JJJJ):");
       String dob = scan.next();
       Date dobDate = new SimpleDateFormat("dd/MM/yyyy").parse(dob);
       searchByIdReturn(id).setDob(dobDate);
   }
   

   }

After the Method I look up the object. First and last name remain unchanged. dob however is was changed as required.

What am I missing?

Thank you so much in andvance!

Answer 1

You never change the fullName which is what I assume you are looking at.

this.fullName = this.firstName + " " + this.lastName;

You don't need to store it, it would be simpler to calculate it each time.

public String getFullName() {
    return this.firstName + " " + this.lastName;
}

---

BTW tests are boolean already so you an write.

public boolean containsId(int id) {
    return this.id == id;
}