using toString()

[Gwen Smith]

I'm trying to print out an array (theList) of objects, and I keep getting something like this: [LContact;@1389e4

I have a toString() method:

public String toString()
	{
		return name+" "+phoneNumber;
	}

and the bit that should print it out

public void list()
	{
		System.out.println(theList.toString());
	}

I think it's the second part that's wrong, but I'm not sure why, or how to make it right.

[Deepak Chopra]

can you please paste declaration of theList object?

[Christophe Verré]

I think it's the second part that's wrong, but I'm not sure why, or how to make it right.

Calling toString on your list (what type is it ? ArrayList ?) will not iterate through it and call the toString method of your list items. You have to loop through the list yourself.

List classes like ArrayList do not override the toString() method, that's why you see the result of the default implementation.

[Gwen Smith]

theList is an array of objects (Contact[])

public class ContactList
{
	
	private int MAX_ENTRIES;
	private Contact[] theList;
	private String phoneNumber;
	private int count;
	private String name;
	
	
	/*
	 * Create a new ContactList that uses filename for storage.
	 * If filename exists, populate the list with the contacts
	 * stored in the file.
	 */
	public ContactList (String filename)
	{
		int MAX_ENTRIES=100;
		theList = new Contact[MAX_ENTRIES];
		int count=0;
	}
	
	/*
	 * Save the current contact list to the file.  Return true
	 * if successful, false if an error occurs.
	 */
	public boolean save()
	{
		/*fix later */
		return false;
	}
		
	/*
	 * Add a new contact
	 *
	 * No checking is done to see if the name is already in the 
	 * contact list.  Adding the same name twice results in 
	 * undefined behavior when search for that contact later.
	 *
	 * Return true if the contact was added, false otherwise.
	 */
	public boolean add(String name, String phone)
	{
		Contact[] thelist = new Contact[count];
		count++;
	
		return true;
	}
	
	/*
	 * Print the current contacts on stdout.
	 */
	public void list()
	{
		theList.toString();
	}
	
	/*
	 * Remove the contact passed as the parameter name.
	 *
	 * If the contact is not currently in the contact list, return
	 * false. 
	 
	 * Return true if the contact is removed.
	 */
	public  boolean remove(String name)
	{
		/* fix later */
		return false;
	}
	
	/*
	 * Print the contact information for name on stdout.
	 *
	 * Return false if the contact is not found, true otherwise.
	 */
	public  boolean lookup(String name)
	{
		/* fix later */
		return false;
	}
}

[Ernest Friedman-Hill]

Christophe Verré wrote:
List classes like ArrayList do not override the toString() method

They do, actually; it's arrays that don't do this, and Gwen has an array.

Gwen, therefore, to do a cheap and easy display of the array's contents, you might convert your array to an ArrayList, something like

System.out.println(new ArrayList(Arrays.asList(theList)));

but to do anything nicer/more customized, you have to use a for-loop to visit each element of the array and print it yourself.

[Christophe Verré]

theList is... an array Well, what I said previously still stands. You have to loop through the array.
And by the way, you don't need to explicitly call toString. System.out.println takes care of that.

[Christophe Verré]

Ernest Friedman-Hill wrote:

Christophe Verré wrote:
List classes like ArrayList do not override the toString() method

They do, actually; it's arrays that don't do this, and Gwen has an array.

My minute of fame

[Mohamed Sanaulla]

If you want to go with the array- You can have a look at- Arrays.toString() method in java.util.Arrays class. But again your Contact class should override toString() to return a meaningful output.

[Campbell Ritchie]

This section in the Java™ Tutorials (and the "arrays" section) should give hints about how to print the individual elements in your array.

[Campbell Ritchie]

Your list() method doesn't do anything.

[Rob Spoor]

Ernest Friedman-Hill wrote:Gwen, therefore, to do a cheap and easy display of the array's contents, you might convert your array to an ArrayList, something like

System.out.println(new ArrayList(Arrays.asList(theList)));

but to do anything nicer/more customized, you have to use a for-loop to visit each element of the array and print it yourself.

I guess you haven't discovered the Arrays.toString methods yet, that Mohamed already mentioned