Thread: Strings not being added to arraylist

Nevermind I figured it out

I am having difficulty adding strings to an array list. I am not getting any error, however, when I check to see if the array list contains the strings that should be in it, it does not.

Nowhere in your code do I see a String being added to an ArrayList - I do see instances of Player. If you want to retrieve a Player based upon name, loop over the List and check for the name, or use a Map

You left out some key details. What does your constructor for Roster actually do? I see that you define teamRoster in class Roster immediately. Do this in the constructor to ensure that it gets executed.

The following code is untested but holds the basic concept of what you are looking for.

public class Team
{
	public Roster roster;
 
	Team()
	{
		this.roster = new Roster();
	}
 
	public static void main(String[] args)
	{
		Team myTeam = new Team();
		System.out.println(myTeam.roster.add(new Player("Java","Java prog")));
		System.out.println(myTeam.roster.add(new Player("1","1.2")));
		System.out.println(myTeam.roster.add(new Player("2","2.2")));
	}
 
}
 
class Roster
{
	ArrayList<Player> playerList;
 
	Roster()
	{
		this.playList = new ArrayList<Player>();
	}
 
	public boolean add(Player player)
	{
		return this.playerList.add(player);
	}
}
 
class Player
{
	private String name;
	private String nickName;
 
	Player(String name, String nickName)
	{
		this.name = name;
		this.nickName = nickName;
	}
 
	Player()
	{
		this("","");
	}
}

The following should net you output of 3 "true"s, each on a separate line.

Read my post above...the ArrayList does not contain Strings - it contains players. If you are using contains() to check for the presence of a String, you will always get false. But I can only guess this is what you are trying to do, because you have not shown us the code which attempts to find the 'String' in the ArrayList

That says that the teamRoster variable is a filename class object, NOT an arraylist. Do you have a class named: filename?
You need to post the definition for the teamRoster variable whose add() method is being called.

If teamRoster was a ArrayList the output would look like this:

      class Testing {}
      ArrayList<Testing> al = new ArrayList<Testing>();
      al.add(new Testing());
      al.add(new Testing());
      System.out.println("al=" + al); // al=[TestCode10$1Testing@addbf1, TestCode10$1Testing@42e816]

Notice the [] around the output

If teamRoster was a ArrayList the output would look like this:

      class Testing {}
      ArrayList<Testing> al = new ArrayList<Testing>();
      al.add(new Testing());
      al.add(new Testing());
      System.out.println("al=" + al); // al=[TestCode10$1Testing@addbf1, TestCode10$1Testing@42e816]

Notice the [] around the output

tR= filename@4e82710e

That says that the teamRoster variable is a filename class object, NOT an arraylist. Do you have a class named: filename?

Originally Posted by noel222

I posted my code in my first post. I am not really sure what you guys are asking me to post. That is all I have. I am not sure why the player names and nicknames are not in the array?

From post #7

Yes, I used the contain method to see if the array contained the players names and nicknames and it does not.

I see nothing in your first post that uses the contains method. If you are using it like this

if ( teamRoster.contains("Mark") ){
 
}

contains will always contain false, as it contains Player objects, not String objects. It helps to post an SSCCE which will more clearly demonstrate the problem.