GUI panels are not showing

I am working on a GUI using matlab r2015b version with multiple panels on it. What im trying to do is only show the panel that is selected on the popup menu (shown on the last picture). However, when i tried to run it, only one panel is showing even though i selected other option. No errors such as reference to non-existent field exist. It only works on the Newtons second law and Newton law of cooling, but on the other two panels, it wont work. Is it a glitch? should i upgrade to 2018 version? or am i missing a small detail? Thanks :)

contents = cellstr(get(hObject,'String'));
  popupmenu1 = contents(get(hObject,'value'));
  
  if strcmp (popupmenu1,'Newtons Second Law of Motion')
  set(handles.second, 'Visible', 'on');
  set(handles.mixture, 'Visible', 'off');
  set(handles.logistic, 'Visible', 'off');
  set(handles.cooling, 'Visible', 'off');
  
  elseif strcmp (popupmenu1,'Mixture Problem')
  set(handles.second, 'Visible', 'off');
  set(handles.mixture, 'Visible', 'on');
  set(handles.logistic, 'Visible', 'off');
  set(handles.cooling, 'Visible', 'off');
  
  elseif strcmp (popupmenu1,'Logistic Growth')
  set(handles.second, 'Visible', 'off');
  set(handles.mixture, 'Visible', 'off');
  set(handles.logistic, 'Visible', 'on');
  set(handles.cooling, 'Visible', 'off');
  
  elseif strcmp (popupmenu1,'Newtons Law of Cooling')
  set(handles.second, 'Visible', 'off');
  set(handles.mixture, 'Visible', 'off');
  set(handles.logistic, 'Visible', 'off');
  set(handles.cooling, 'Visible', 'on');
  
  end

[Cris LaPierre]

should i upgrade to 2018 version?

You need to measure the impact that may have on your workflow, but 9 times out of 10, the answer is yes. There are so many new features you are missing out on!

[Ma.Cathyrine Ravina]

Okay :) I can still copy the codes i have on my previous work, right? :)

Answer 1

[Cris LaPierre]

Your code logic looks good. The issue, I think, is that you are indexing incorrectly into contents to assign a value to popupmenu1. Your code is

contents(get(hObject,'Value'))

but the code Guide provides in the callback hint is

contents{get(hObject,'Value')}

Note the use of curly braces {}

[Cris LaPierre]

I was testing in 15a so thought I'd share what my callback for the popupmenu looks like.

% --- Executes on selection change in popupmenu1.
function popupmenu1_Callback(hObject, eventdata, handles)
% hObject    handle to popupmenu1 (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)

% Hints: contents = cellstr(get(hObject,'String')) returns popupmenu1 contents as cell array
%        contents{get(hObject,'Value')} returns selected item from popupmenu1

contents = cellstr(get(hObject,'String'))
switch contents{get(hObject,'Value')}
    case 'Panel1'
        handles.uipanel1.Visible = 'on';
        handles.uipanel2.Visible = 'off';
        handles.uipanel3.Visible = 'off';
    case 'Panel2'
        handles.uipanel2.Visible = 'on';
        handles.uipanel1.Visible = 'off';
        handles.uipanel3.Visible = 'off';
    case 'Panel3'
        handles.uipanel3.Visible = 'on';
        handles.uipanel1.Visible = 'off';
        handles.uipanel2.Visible = 'off';
end

[Ma.Cathyrine Ravina]

Wonderful!! It works :)))) thank you so much :)