MATLAB: Help with If else statements

ifelse

I wrote a script that reads data from the internet and predicts the winner of a football game. The model I use assigns a total of 10 points to each team, so the closest win is 6-4 or a 5-5 draw. I display the winner of the game in the GUI with a text box with the code,
if true
  % code

if TeamAScore > TeamBScore  
    set(handles.text4,'String', TeamAName);
else
    set(handles.text4,'String', TeamBName);
end;
  end
This works great, but I wanted to spruce it up by letting the user know how big the win is. So I wrote,
if true
%Display winner
WinBig = ' wins big.';
WinComfort = ' wins comfortably';
WinClose = ' wins close';
if TeamAScore >= 9 
  disp(TeamAName); %win big
  NewName = [TeamAName, WinBig];
  set(handles.text4,'String', NewName);
elseif TeamAScore == 8 || 7 
  disp(TeamAName); % comfortable win

  NewName = [TeamAName, WinComfort];
  set(handles.text4,'String', NewName);
elseif TeamAScore == 6 
  disp(TeamAName); % close win

  NewName = [TeamAName, WinClose];
  set(handles.text4,'String', NewName);
elseif TeamBScore >=9 
  disp(TeamBName); % win big
  NewNameB = [TeamBName, WinBig];
  set(handles.text4,'String', NewNameB);
elseif TeamBScore == 8 || 7
  disp(TeamBName); % comfortable win
  NewNameB = [TeamBName, WinComfort];
  set(handles.text4,'String', NewNameB);
elseif TeamBScore == 6
  disp(TeamBName); % close win
  NewNameB = [TeamBName, WinClose];
  set(handles.text4,'String', NewNameB);
elseif TeamBScore == TeamAScore 
  disp('Too close to call'); % too close to call
  set(handles.text4,'String', 'Too close to call');
end;
    % code
  end
But this gives me TeamA everytime, not sure why. Any help is appreciated.

Best Answer

Your first elseif is always going to be true. Why? Because you are ignoring MATLAB's rules of operator precedence. Check this out:
>> TeamAScore = 5;
>> TeamAScore == 8 || 7
ans =
     1
Does this mean that 5 is equal to either seven or eight? Of course not, we just need to follow the basic operator precedence rules that we were taught in highschool (and shown in the link above), so we know that this code is really equivalent to:
>> (TeamAScore == 8) || 7
ans =
     1
>> 0 || 7
ans =
     1
where seven is true because it is non-zero. When you pay attention to the operator precedence rules then you would probably have written something like this:
>> TeamAScore == 7 || TeamAScore == 8
ans =
     0
Or more compactly:
>> any(TeamAScore == [7,8])
ans =
     0
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