Printing Method (inheritance and super method)

[o moyse]

Hi there

I have been studying java for over a week,it was going well until now

I have a question about inheritance and super method

I have 3 classes Person, Student , Employee.


I was expecting something like

"joe",25,"new york","2212-55-1212
"bob",40,"boston","617-55-1212",20000.99


So now i am confused

Can you help me !!!

 



public class Person {
	private String name;
	private String address;
	private String phone;
	private int age;

	public Person(String n, int ag, String ad, String p)
	{
		name=n;
		age=ag;
	    address= ad;
		phone=p;
		
		
	}// End Constructor
	
	public String getName()
	{
		return name;
	}
	
	public int getAage()
	{
		return age;
	}
	
	public String getAdress()
	{
		return address;
	}
	
	public String getPhoneNumber()
	{
		return phone;
	}
	
	public void setAddres(String newAddress)
	{
		address=newAddress;
		
	}
	public void setPhoneNumber(String newPhone)
	{
		phone=newPhone;
	}
}// End main




public class Student extends Person{
    private double gpa;
    
    public Student (String n, int ag, String ad, String p, double g)
    {
        super(n,ag,ad,p);
        gpa=g;
        
    }
    
    public  String toString()
    {
        return super.toString()+getGPA();
    }
    
    public double getGPA()
    {
        return gpa;
        
    }

public class Employee extends Person{
    private double salary;
    
    public Employee (String n, int ag, String ad, String p, double s)
    {
        super(n,ag,ad,p);
        salary=s;
        
    }
    
    public  String toString()
    {
        return super.toString()+getSalary();
    }
    
    public double getSalary()
    {
        return salary;
        
    } 

   
}//end main


   

 

public class PersonDemo {

	public static void printAll(Person[] arr)
	{
		for(int i=0; i < arr.length; i++ )
		{
			if(arr[i] !=null)
			{
				System.out.println("["+i+"]");
				System.out.println(arr[i].toString());
				
			}
		}
	}
	
	
	
	public static void main(String[] args) {
		
		Person [] p = new Person[4];
		p[0]=new Person ("joe",25,"new york","2212-55-1212");
		p[1]=new Student("jill",30,"chicago","324-88-454",4.0);
		p[3]=new Employee("bob",40,"boston","617-55-1212",20000.99);
                
                printAll(p);                                *************************  This is my question *****************
                                                             

			
		

	}

}//End main



*****************************************************
  When i run the program the result is

[0]
Person@23fc4bec
[1]
Student@8dc85694.0
[3]
Employee@7150bd4d20000.99

I was expecting something like 

"joe",25,"new york","2212-55-1212
"bob",40,"boston","617-55-1212",20000.99


Can you help me !!!!!!!!!!!!!!!!!!!!!!



   

[Sudipta Laha]

hi..

you are printing the objects not the values of your member variables. so you are getting such results.
try to get the object from your array and try using the getter methods to get your desired output.

[Wouter Oet]

Hi and welcome to the JavaRanch.

You where well on your way but you need to override the toString in person. Because the Object's implementation of it just return the classname + @ + memorylocation in hex.

[o moyse]

Thank you for your quick reply

I used System.out.println("Name " +arr[i].getName()+" Adress: "+arr[i].getAdress());

I see what you mean now, it was a refence to the object.

[o moyse]

Just out of curiosity is there a better way to print the values of my objects or a better data structure to store an get the values of my objects ???

[Wouter Oet]

The use of the toString() method is a common way to print the values of an Object. It's the reason behind the existence of the method. It is sufficient for simple printing/debugging but when it gets complexer you should separate data and presentation. In your case you could replace the the for loop and use the enhanced for loop instead. Also the System.out.println() method automatically uses the toString() method is the parameter is an Object reference (i.e. not a primitive) and the value is not null. So the toString() is unnecessary.