Reference to non-existent field error

Hello Everyone. I am getting an error related to

Reference to non-existent field 'mystructdata'.

Error in GUI_ParametersFinal>pushbutton_Save_Callback (line 120)

data = handles.mystructdata;

Error in gui_mainfcn (line 95)

feval(varargin{:});

Error in GUI_ParametersFinal (line 42)

gui_mainfcn(gui_State, varargin{:});

Error in @(hObject,eventdata)GUI_ParametersFinal('pushbutton_Save_Callback',hObject,eventdata,guidata(hObject))

When I do not type any value inside the edit text boxes, it gives me this error when saving inside the mat file. How can I remove this error and save another value only, which is needed and not related to my struct fields.

My code for pushbutton save_ callback is this:

function pushbutton_Save_Callback(hObject, eventdata, handles)

startingFolder = pwd

defaultFileName = fullfile(startingFolder, '*.mat');

[baseFileName, folder] = uiputfile(defaultFileName, 'Select mat file');

if baseFileName == 0

return;

end

fullFileName = fullfile(folder, baseFileName);

if (exist('str') == 0); or if(exist('handles.mystructdata') == 0)

data.Level = handles.Level;

save(fullFileName,'data')

else

data = handles.mystructdata;

data.Level = handles.Level;

save(fullFileName,'data');

end

If I dont type anything inside the edit text boxes, I will like these text boxes to be ignored and just save that text box value in which I typed a value using structs fields. Thank you so much.

[Walter Roberson]

if (exist('str') == 0); or if(exist('handles.mystructdata') == 0)

That is not correct syntax for or.

if ~exist('str', 'var') || ~isfield(handles, 'mystructdata')

Answer 1

[Adam]

exist('handles.mystructdata')

does not work for struct fields.

isfield( handles, 'mystructdata' )

is what you should use to check if the field exists.

[Stephen23]

See the last line of my comment to your earlier question:

https://www.mathworks.com/matlabcentral/answers/486120-saving-and-uploading-data-with-any-file-name#comment_757785