Undefined operator '*' for input arguments of type 'matlab.ui​.control.U​IControl'.

The following function is giving an error,

function tf = GUI_ListBoxAdd(vH, bUni, vStr, vID);
% Add an entry to a GUI list box.
%
% Sucess = GUI_ListBoxAdd(HandleTagName, Unique, String, Number)
% Sucess = GUI_ListBoxAdd([], Unique, String, Number)
%
% If Unique is 1 and String is already in the list, then this
% function will not add another copy of the item. If Number
% is not specified it will be set to the numerical value of
% the string, or 0. String can be a cell matrix containing
% a string list or a list box matrix. Number can be a vector
% containing numbers associated with a string list. A non-GUI
% list box matrix is a cell matrix that is not associated
% a GUI list box object.
%
% If HandleTagName is not specified (empty) then a non-GUI
% list box matrix will be created; call the GUI_ListBoxCopy()
% function to access it.
%
% Call the GUI_ListBoxClear() function when the list box is
% no longer required.
%
% See also GUI_GetID.

% Intialize for fail case!
tf = 0;

if isempty(vH)
    sGlobal = 'GUI_ListBox';
else
    hObj = GUI_GetID(vH);

      if hObj == 0;
          return;
      end;

      aaa = hObj * 1e7;

      sGlobal = sprintf('GUI_ListBox_%012ld', Trunc(aaa));
  end

try
vID = vID;
bSet = 1;
catch
vID = NaN;
bSet = 0;
dID = NaN;
end

% If a message box cell matrix is passed then
% set vID with the numeric part.
[iStrR iStrC] = size(vStr);
if iscell(vStr);
    if iStrC > 1;
        bSet = 1;
        vID = zeros(1, iStrR);
        for iSub = 1 : iStrR;
            vID(iSub) = vStr{iSub, 2};
        end;
    end;
else;
    vStr = {vStr};
end;

% If vID has been specified, it must have the same
% length (rows) as vStr.
iLenID = length(vID);
if bSet & (iStrR ~= iLenID)
    return;
end

eval(sprintf('global %s;', sGlobal));
eval(sprintf('vTmp = %s;', sGlobal));

% If bUni is true then check for repeated values before adding

for iInSub = 1 : iStrR;
    sStr = vStr{iInSub, 1};
    if bSet;
        dID = vID(iInSub);
    end;

      [iLen iNull] = size(vTmp);

      if iLen < 1;
          iSub = 1;
      else;
          if bUni == 1;
  % If not found then add the unique value
              if FindInStrList(sStr, vTmp(:, 1)) == 0;
                  iSub = iLen + 1;
              else;
                  iSub = 0;
              end;
          else;
              iSub = iLen + 1;
          end;
      end;

      if iSub > 0;
          vTmp{iSub, 1} = sStr;
          if bSet;
              vTmp{iSub, 2} = dID;
          else;
              vTmp{iSub, 2} = atof(sStr);
          end;
          tf = 1;
      end;

end;

% Set the listbox with the new list
eval(sprintf('%s = vTmp;', sGlobal));
if ~isempty(vH);
        %set(handles.listbox1, 'String', prev_str, 'Value', length(prev_str));

          set(hObj, 'String', vTmp(:, 1),'Value', length(vTmp(:, 1)));
  end;

Error

Undefined operator '*' for input arguments of type 'matlab.ui.control.UIControl'.

Error in GUI_ListBoxAdd (line 37)
    aaa = hObj * 1e7;

Error in Scratch>pushDet_Callback (line 258)

Error in gui_mainfcn (line 95)
        feval(varargin{:});

Error in Scratch (line 17)
    gui_mainfcn(gui_State, varargin{:});

Error while evaluating UIControl Callback

Answer 1

[Walter Roberson]

Change

aaa = hObj * 1e7;

to

aaa = double(hObj) * 1e7;