Thread: The order of logic in my Java Code

I've been a professional developer for a lot of my career.. I'm a beginner at Java but not at Coding. The problem below is just a training exercise as such but I'd like to understand whats going on. I'm just trying to build a LIST of elements. Please excuse me that I choose it to be a list of English Football teams.. that's just a detail.

So I have defined my own class 'Team', and I'm building a List of TEAMs. I set the values of my three attributes (2 public, one private), print out some of the detail, add to the list...repeat 3 times... then print to the list

And my list is just the last item, added 4 tines. I've experimented with using different variable names for my Team in the Main class, and that fixes it... But I would expect my instance of team to have different values each time I add it.

      Team NextTeam = new Team();
 
     List<Team> premL = new ArrayList<Team>();
 
     NextTeam.CityName = "Preston";
     NextTeam.ExtraName = "North End";
     NextTeam.setColour("Blue");
     System.out.println(NextTeam);
     premL.add(NextTeam);
 
 
 
 
     NextTeam.CityName = "Plymouth";
     NextTeam.ExtraName = "Argyle";
     NextTeam.setColour("Green and black");
 
     premL.add(NextTeam);
     System.out.println(NextTeam.toString());
 
     NextTeam.CityName = "Manchester";
     NextTeam.ExtraName = "City";
     NextTeam.setColour("Light Blue");
     premL.add(NextTeam);
 
     System.out.println(NextTeam);
 
     NextTeam.CityName = "Gillingham";
     NextTeam.ExtraName = "";
     NextTeam.setColour("Blue");
     premL.add(NextTeam);
     System.out.println(NextTeam);
 
     Team.printTeams(premL);
 
    }
}

OUTPUT :
Team{CityName='Preston', ExtraName='North End'}
Team{CityName='Plymouth', ExtraName='Argyle'}
Team{CityName='Manchester', ExtraName='City'}
Team{CityName='Gillingham', ExtraName=''}
Gillingham
Gillingham
Gillingham
Gillingham


If I use a different 'variable' name for my Team, that does fix it, but that's not the point; I'm trying to understand what is going on
(Only changed code here, the 2nd team added using a different variable name

     ExtraTeam.CityName = "Plymouth";
     ExtraTeam.ExtraName = "Argyle";
     ExtraTeam.setColour("Green and black");
 
     premL.add(ExtraTeam);
     System.out.println(ExtraTeam.toString());

Then the output is;
Team{CityName='Preston', ExtraName='North End'}
Team{CityName='Plymouth', ExtraName='Argyle'}
Team{CityName='Manchester', ExtraName='City'}
Team{CityName='Gillingham', ExtraName=''}
Gillingham
Plymouth Argyle (note change)
Gillingham
Gillingham

I am not sure I understand the problem. Can you explain what the problem was?
You have posted some output but have not said if anything was wrong with that output
or if you expected different output.
If you expected different output could you add some comments to describe what you want to be different?
For example
jones <<<<<<<< THIS SHOULD BE smith

use a different 'variable' name

Changing a variable name should not have any effect on what is printed (unless you are using Reflection which looks inside of a class).


Note: I only see one instance of the Team object being created. It is added to the list multiple times.
So the list has several references to instances of the same object in it.
The contents of that object is changed several times, but at the end there is only one object with several references all pointing to that one instance.


Please edit your post and wrap your code with code tags:

[code]
**YOUR CODE GOES HERE**
[/code]

to get highlighting and preserve formatting.

at the point the .add method is called, the value of the instance at that point is used.

The add method saves a copy of the reference to the object. It does not save a copy of the contents of the object.

If I use a different 'variable' name

Where is the variable: ExtraTeam declared and given a value? The posted code does not show that.