Thread: newby Questions - indexOf help with an ArrayList

I'm trying to build an address book application, but before I start I'm familliaring my self with arrayLists of objects.

I have two classes (and a third tester class):
DirectoryEntry
PhoneDirectory

DirectoryEntry has a constructor that takes in two strings as arguments and saves then in class variables, name and number.

(for now) all PhoneDirectory does is ceate an arraylist:

dir = new ArrayList<DirectoryEntry>

and has a method to add an entry to the array list.

I want to us the indexOf("Stephen") to return an index number in the array, right now all I'm getting is -1.
What bugs me is that if I put something like:

DirectoryEntry name = dir.get(1);

I get the name and number in slot 4. I'm just not understanding the indexOf() and OOP : S please any help would be most welcome

public class Driver
{
 
        public static void main(String[] args)
        {
            PhoneDirectory phone = new PhoneDirectory();
            phone.addEntry("Stephen", "447-8067");
            phone.addEntry("Vickie", "415-8006");
            phone.addEntry("Jake", "675-8064");
            phone.addEntry("Jen", "879-5684");
            phone.addEntry("Anna", "710-4564");
 
            phone.displayContents();
 
        }
 
 
 
}

import java.util.ArrayList;
 
 
public class PhoneDirectory {
 
    public ArrayList<DirectoryEntry> dir;
 
    public PhoneDirectory()
    {
        dir = new ArrayList<DirectoryEntry>();
    }
 
    public void addEntry(String name, String number)
    {
        dir.add(new DirectoryEntry(name,number));
 
    }
 
    public void displayContents()
    {
 
       // DirectoryEntry aName = dir.get(3);
        int ind = dir.indexOf("Stephen");
 
        System.out.println(ind);
    }
}

public class DirectoryEntry {
    private String name;
    private String number;
 
    public DirectoryEntry(String name, String number)
    {
        this.name = name;
        this.number = number;
    }
 
    public String name()
    {
        return name;
    }
 
@Override
     public String toString()
    {
        return name + " " + number;
    }
}

I want to us the indexOf("Stephen") to return an index number in the array,

Is the String "Stephen" an object in the ArrayList?
Or is it inside of another object, a DirectoryEntry?
It looks like the ArrayList contains DirectoryEntry objects, not Strings.

I won't call you cynical but I will call you cautious...Sorry, the actual code was:
do
DirectoryEntry aName = dir.get(3); < - This actually does work, as you can see I'm using get on a DirectoryEntry object - I just don't know how to do something like this to search and get an index number. if I do this:

DirectoryEntry aName = dir.indexOf("Stephen"); I get bupkis

DirectoryEntry aName = dir.indexOf("Stephen"); I get bupkis

To find the element in the list with that contents you will need a loop that looks at each element in the list and tests if it contains the contents you want.