Thread: Address Book Program Issues

Though i seem to have an issue.
After entering 2 contacts and then requesting to view the list i got this printed for some strange reason

Street Address: townsend croft, City: coventry, County: west midlands, Country united kingdom, Postcode: null
Forename: philip, Surname: stone

1 Postcode:Contact@70453807
Street Address: townsend croft, City: coventry, County: west midlands, Country united kingdom, Postcode: null
Forename: philip, Surname: stone

2 Forename:Contact@5bcdbf6
Street Address: weston gardens, City: isleworth, County: london, Country united kingdom, Postcode: null
Forename: richard, Surname: stone

2 Surname:Contact@5bcdbf6
Street Address: weston gardens, City: isleworth, County: london, Country united kingdom, Postcode: null
Forename: richard, Surname: stone

2 Street:Contact@5bcdbf6
Street Address: weston gardens, City: isleworth, County: london, Country united kingdom, Postcode: null
Forename: richard, Surname: stone

2 City:Contact@5bcdbf6
Street Address: weston gardens, City: isleworth, County: london, Country united kingdom, Postcode: null
Forename: richard, Surname: stone

2 County:Contact@5bcdbf6
Street Address: weston gardens, City: isleworth, County: london, Country united kingdom, Postcode: null
Forename: richard, Surname: stone

2 Country:Contact@5bcdbf6
Street Address: weston gardens, City: isleworth, County: london, Country united kingdom, Postcode: null
Forename: richard, Surname: stone

2 Postcode:Contact@5bcdbf6
Street Address: weston gardens, City: isleworth, County: london, Country united kingdom, Postcode: null
Forename: richard, Surname: stone

Your program appears to be in a loop, repeatedly printing out the last entry in the list.
Look at your logic to see why the code in the loop does not move the next item in the list or exit the loop.

Why do you create new objects in the viewEntries method? All the entries to be viewed should be in the list.

It seemed the only way to get it to compile.
I require this - addressbook.viewContact(contact); so it links to addressbook and performs the function.
And it says it can't find the variable contact.
It ends up going back to having

Name name = new Name(forename, surname);
Postcode postcode = new Postcode(post);
Address address = new Address(street, city, county, country);
Contact contact = new Contact(name, address);

and then it can't find the variables its what i have in my addcontact method

As for the loop in my AddressBook i am using

public void viewContact(Contact contact)
        {
             for( int index = 0; index < top; index++)
                {
                    System.out.println((index+1)+" Forename:"+
                    list[index].toString());
                    System.out.println((index+1)+" Surname:"+
                    list[index].toString());
                    System.out.println((index+1)+" Street:"+
                    list[index].toString());
                    System.out.println((index+1)+" City:"+
                    list[index].toString());
                    System.out.println((index+1)+" County:"+
                    list[index].toString());
                    System.out.println((index+1)+" Country:"+
                    list[index].toString());
                    System.out.println((index+1)+" Postcode:"+
                    list[index].toString());
 
                }
        }

So

 for (Contact index : list)
             {
                 System.out.println(index.toString());
             }

This says for each Contact index in list then system prints out the index and the toString method. wait it can't be index that would print out the number not the data

What class is the list variable?
What does that class's to String method return?
In the code you posted, you call the toString method seven times for each index's value.

The list variable is in the class AddressBook set as an array

private Contact[] list;

The toString method comes from Contact class

@Override  
    public String toString() {  
        return super.toString() + "\n" + address + "\n" + name + "\n";  
    }

returning the name and address variables

You need to think about what data you want to print and where that data is located.
What is in the list array?
If you get an object from the list array, what does it contain? How do you get the pieces of data you want to print from the object that you get from the array?

The data i want to print is all the variables from name and all the variables from address.
All of which is found under

Name name = new Name(forename, surname);
            Postcode postcode = new Postcode(post);
            Address address = new Address(street, city, county, country);
                        Contact contact = new Contact(name, address);

My list array contains - list[top] = contact; so the index number basically
If i get an object from it, it contains the index number and contact which contains the name and address variables

You need to design what is to go on each line that you print out.
Then you need to figure out where each piece of data on that line comes from.
Then you can write the code to print out that line with all those pieces of data.

So i need

for (Contact top : list)
             {
                 System.out.println(top.toString());
             }

??

try it an see what happens.

It compiles but i get an error message when i use the method - "java.lang.NullPointerException: null"
error message points System.out.println(top.toString());
It's seems to show everything but it gives null for the postcode

Please show the FULL output.

Contact@3bc0f2e5
Street Address: west, City: south, County: east, Country north, Postcode: null
Forename: phil, Surname: stone

Contact@788ab708
Street Address: south , City: east, County: north, Country west, Postcode: null
Forename: rich, Surname: smith


"java.lang.NullPointerException
at AddressBook.viewContact(AddressBook.java:49)
at AddressTextUi.viewEntries(AddressTextUi.java:123)
at AddressTextUi.displayMainMenu(AddressTextUi.java:4 6)
at AddressTextUi.mainMenu(AddressTextUi.java:14)
at AddressbookDriver.main(AddressbookDriver.java:10)"

Look at this simple program segment. If the array contains null, null is returned by the for each:

      String[] list = new String[3];  // create with 3 slots
      list[0] = "test";                     //only put element in one
      for(String s : list) {                // read all slots including emptys
        System.out.println("s=" + s);
      }
/*  The print out from the above
s=test
s=null
s=null
*/

Your code must test for a null value before using it.

Okay that makes sense but where and how do i do this? Sorry my brain has melted

Don't use the for each loop. You have a variable with the number of contacts in the list. Use a normal loop with the value of that variable controlling the number of loops.

Is this something different to the null thing?
so my variable is list[top]
so i need to use the top and that sets the amount of loops,
i really can't think anymore

What value is in the top variable?
Is it the index of the last element in the list or is it the count of the number of items in the list?

I have these

//index of the last entry
private int top = 0;
//constant number that indicates the maximum
//number of entries in the address book
private static final int MAXENTRIES = 5;
//array of Address Book Entries
private Contact[] list;

I don't think you answered my question.
What value is in the top variable?
Is it the index of the last element in the list or is it the count of the number of items in the list?

Or is it the index for the next item to be added to the list. This would often be the same as the number of items in the list