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Thread: How do I return an array list?

  1. #1
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    Question How do I return an array list?

    Ok, so to ensure everything is working ok, i want to be able to return my data from my array list. The code is below and if anyone can tell me how i could return the data (preferabley by printing it. Thanks

    import java.util.ArrayList;
     
    public class ContactList
    {
        private ArrayList<Contact> contactList;
        private ArrayList<Contact> aContact;
        private String contactType;
     
        public ContactList()
        {
     
            contactList = new ArrayList<>();
            aContact = new ArrayList<Contact>();
            ArrayList<Contact> contactList = new ArrayList<Contact>();
        }
         public void addPersonalContact(String fName, String sName, String street, String town, String partOnePC, String partTwoPC, String phonenumberEmail)
        {
            contactList.add(new AddPersonalContact(fName, sName, street, town, partOnePC, partTwoPC, phonenumberEmail));
     
     
        }
     
     
     
        //public void addBusinessContact(String fName, String sName, String street, String town, String partOnePC, String partTwoPC, String phonenumberEmail)
        //{
          //  contactType = "Business";
            //aContact.add(new Contact(fName, sName, street, town, partOnePC, partTwoPC, phonenumberEmail));
     
     
     
        //}
     
     
     
    }
    Last edited by 93tomh; July 26th, 2012 at 01:12 AM.


  2. #2
    Super Moderator jps's Avatar
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    Default Re: How do I return an array list?

    All you have to do is go through the list and System.out.println each one, which is how i used to do it long ago, but most of the time these days i find myself watching things in the debugger

    If you don't know how to go through each element in your array list, look up the iterator class

  3. #3
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    Default Re: How do I return an array list?

    public ArrayList/*<type>*/ methodName(/* parameters */)
    	{
    		ArrayList arraylist = new ArrayList();
    		/**
    		 * code here
    		 */
     
    		return arraylist;
    	}
     
    	/**
    	 * or
    	 */
     
    	public ArrayList arrayList = new ArrayList();
     
     
    	public ArrayList/*<type>*/ method2Name(/* parameters */)
    	{
    		return arrayList;
    	}

    You should read up on returning something. If you are using a method, the second word typed is what is returned. Void means it returns nothing, boolean means you have to return a boolean. int means you have to return an int and so on. It can be done with any object you create. Try experimenting with methods that return something. For instance, in ArrayList, the size() method returns an int of how long the ArrayList is.


    public void name(String name){System.out.println(name);}
     
    //could be
     
    public String name(String name)
    {
        return name;
    }

    What is returned is completely up to you and the purposes of the method you are writing.

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