Using toString() method in Java

Question

I am trying to utilize the toString() in a class I have called Employee(). I have a 1D array of type Employee, which stores Employee Data, which include the Employee ID, Employee Name, Employee Address, and Employee Hire Date. I want the user to specify the amount of employees, and then enter the relevant data for however many employees the user wants. I then want to print the result for the user with the information entered. I keep getting some results that are null. I tried using an If statement that printed output if it didn't equal null, but that didn't work. I know the output works if I print out a single variable, such as address, but I want all variables to print out. Thank you for any help.

public class Address
{
  public String address;

  public void getAddress(String a)
  {
      address = a;
  }

  public String toString()
  {
      return address;
  }

}
public class Name
{
  String name;

   public void getName(String n)
  {
      name = n;
  }

  public String toString()
  {
      return name;
  }

}
public class Date
{

    public String date;
    public String date1;


    public void getDate(int d, int m, int y)
    {

        date1 = (m + "/" + d + "/" + y);

    }    

    public String toString()
    {
        return date1;
    }

}

import java.util.Scanner;

public class Employee
{
    private int number;
    private Name name1 = new Name();
    private Address address1 = new Address();
    private Date hireDate = new Date();
    String number1;

    public void getDate1(int d, int m, int y)
    {
        hireDate.getDate(d, m, y);
    }

    public void getID(int x)
    {
        number = x;


    }

    public void setName( String n)
    {
        name1.getName(n);
    }

    public void getAddress(String a)
    {
         address1.address = a;
    }

    String z;

    public String toString()
    { 

        number1 = String.valueOf(number);
        String name2 = String.valueOf(name1);
        String address2 = String.valueOf(address1);
        String hireDate2 = String.valueOf(hireDate);

        z = number1 + " " + name2 + " " + address2 + " " + hireDate2;
        return z; 
    }


    public static void main(String args[])
    {
        Scanner input = new Scanner(System.in);

        System.out.println("Please enter amount of Employees: ");
        int input1 = input.nextInt();
        input.nextLine();

        for (int i = 0; i < input1; i++)
        {
            Employee [] employees = new Employee[4];

            System.out.println("Please enter the employee ID: ");
            int employeeID = input.nextInt();
            input.nextLine();
            employees[0] = new Employee();
            employees[0].getID(employeeID);

            System.out.println("Please enter the employees Name: ");
            String name2 = input.nextLine();
            employees[1] = new Employee();
            employees[1].setName(name2);

            System.out.println("Please enter the employee's address: ");
            String address2 = input.nextLine();
            employees[2] = new Employee();
            employees[2].getAddress(address2);

            System.out.println("please enter hire date, day (1-31),");
            System.out.print("month (1-12), year (1901 - 2019) in order on seperate");
            System.out.print(" lines: ");
            int input2 = input.nextInt();
            int input3 = input.nextInt();
            int input4 = input.nextInt();

            employees[3] = new Employee();
            employees[3].getDate1(input2, input3, input4);

            for (int p = 0; p < employees.length; p++)
            {
                System.out.println(employees[p]);
            }

        }

    }  
}

Answer 1

Use String

Your name & address classes consist of merely a string. So no need to invent those classes at all.

java.time.LocalDate

Your Date class consists of two strings, but you only use one of them. So instead, just use the java.time.LocalDate class bundled with Java 8+.

Records

If the main purpose of your class is to transparently communicate shallowly-immutable data, then declare your class as a record. The compiler implicitly implements constructor, getters, equals & hashCode, and toString.

Be aware that you can declare a record locally within a method as well as externally in separate .java file. Ditto for enums and interfaces now as well. This is new in Java 16+.

So your entire Employee class becomes simply:

record Employee ( int id , String name , String address , LocalDate hired ) {}

Instantiate:

Employee alice = new Employee ( 101 , "Alice" , "11 Main St" , LocalDate.of( 2022 , Month.JANUARY , 23 ) ) ;

Generate text by calling toString.

String output = alice.toString() ; 

Employee[id=101, name=Alice, address=11 Main St, hired=2022-01-23]

Answer 2

I have create classes which were needed. You can change them but you are creating employee object every time. I have corrected the code debug it and you will know what was wrong.

import java.util.Calendar;
import java.util.Date;
import java.util.Scanner;

class Name {

    private String name;

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

}

class Address {
    private String address;

    public String getAddress() {
        return address;
    }

    public void setAddress(String address) {
        this.address = address;
    }

}

public class Employee {

    private int number;
    private Name name1 = new Name();
    private Address address1 = new Address();
    private Date hireDate = new Date();
    String number1;

    public void getDate1(int d, int m, int y) {
        Calendar calendar = Calendar.getInstance();
        calendar.set(y, m, d);
        hireDate = calendar.getTime();
    }

    public void getID(int x) {
        number = x;

    }

    public void setName(String n) {
        name1.setName(n);
    }

    public void getAddress(String a) {
        address1.setAddress(a);
    }

    String z;

    public String toString() {

        number1 = String.valueOf(number);
        String name2 = name1.getName();
        String address2 = address1.getAddress();
        String hireDate2 = String.valueOf(hireDate);

        z = number1 + " " + name2 + " " + address2 + " " + hireDate2;
        return z;
    }

    public static void main(String args[]) {
        Scanner input = new Scanner(System.in);
        System.out.println("Please enter amount of Employees: ");
        int input1 = input.nextInt();
        input.nextLine();

        Employee[] employees = new Employee[input1];
        for (int i = 0; i < input1; i++) {

            System.out.println("Please enter the employee ID: ");
            int employeeID = input.nextInt();
            input.nextLine();
            employees[i] = new Employee();
            employees[i].getID(employeeID);

            System.out.println("Please enter the employees Name: ");
            String name2 = input.nextLine();
            employees[i].setName(name2);

            System.out.println("Please enter the employee's address: ");
            String address2 = input.nextLine();
            employees[i].getAddress(address2);

            System.out.println("please enter hire date, day (1-31),");
            System.out.print("month (1-12), year (1901 - 2019) in order on seperate");
            System.out.print(" lines: ");
            int input2 = input.nextInt();
            int input3 = input.nextInt();
            int input4 = input.nextInt();

            employees[i].getDate1(input2, input3, input4);

            System.out.println(employees[i]);

        }

    }
}