Printing out each item in an arraylist

Question

Im trying to list the items in an array list from another class.

I have 3 classes in total

Tell - The main program

Item - The class that creates individual telephone directory items

Directory - A directory object which stores all the items.

What I'm trying to do is list all the items within the array list created in "directory" and im doing it like this....

TELL

if (Directory.entries.size>0)
{
     for (int i=0; i<Directory.entries.size(); i++) // Check size of array
     {
           Directory.entries.get(i).showRecord();
     }
}

DIRECTORY

public void printItem()      
{
     //I HAVE NO IDEA WHAT GOES HERE
}

ENTRY

public class Entry
{
String name;
String telNo;
public Entry(String aName, String aTelNo )
{
    setNumber(aTelNo);
    setName(aName);
}
// Add methods here
private void setNumber(String aTelNo)
{
    telNo = aTelNo;
}

public String getNumber()
{
    return telNo;
}

private void setName(String aName)
{
    name = aName;
}

public String getName()
{
    return name;
}

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


}

However I havnt got the foggiest what needs to go in the printItem() Method to allow me to print the individual items in the directory.

Could someone point me in the right direction? This is the first time I have ever really used array lists accross multiple classes and I'm very confused.

Answer 1

Since you have overrided the toString in your Entry class, so what all you need to do is iterate over your List and print each item. It will automatically invoke the toString of your Entry class and print the returned value: -

Put this code in your print method, which is in Directory class.

public static void print() {
    for (Entry entry: Directory.entries) {
        System.out.println(entry);
    }
}

entries is the static list you have in your Directory class.

And from your Tell class, just invoke your print method:-

Directory.print();

Answer 2

Right now you don't have a call to printItem() ; I am assuming your call to .showRecord() is either going to replace printItem() or be removed because they are trying to accomplish the same thing.

Assuming that you remove .showRecord() and just use printItem() instead, and that you are using some type of collection with data member named entries inside the Directory class:

public void printItem() {
    for (Entry entry : this.entries) {
        System.out.println(entry);
    }
}

is all you need since you already overrode the toString() function inside your Entry class. This iterates through each entry in the directory for you and prints them on at a time on separate lines.

Answer 3

You can use TreeMap<String, String> to hold the telephone directory list of items. TreeMap will ensure that your keys are sorted in Natural order (by person name) and that there are no duplicate names in the directory (every persons name is unique ). To print an entry would be a simple String treeMap.get(key);