Comparing input character and a String

Hello, I am trying to design a GUI. In my GUI, Matlab gives 5 random characters and user will enter the same. I want to compare user's input and 5 characters that MATLAB gives for create a ratio called correction. correction ratio = how many characters are true / 5. For ex = if 1 character of MATLAB and user input is same, correction ratio = 1/5. I try to make this code but it gives error. How can i do that ?

function check_Callback(hObject, eventdata, handles)
% hObject    handle to check (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
b1= get(handles.input,'String') % user's input
a1 = get(handles.q1,'String'); % 1st character of MATLAB's string
a2 = get(handles.q2,'String'); % 2nd character of MATLAB's string
a3 = get(handles.q3,'String'); % 3rd character of MATLAB's string
a4 = get(handles.q4,'String'); % 4th character of MATLAB's string
a5 = get(handles.q5,'String'); % 5th character of MATLAB's string
correction = 0;
for i = 1:5 %% this is for obtaining correction ratio. 
    if a(i)== char(b1(i))
        correction = (correction + i)/5;
    end
end

[Bob Thompson]

Please post the entire error message.

[Yusuf Oguzhan Turgut]

a =

5

b1 =

'$>-&\'

Undefined function or variable 'a'.

Error in guioguzhan>check_Callback (line 353)

if a(i)== char(b1(i))

Error in gui_mainfcn (line 95)

feval(varargin{:});

Error in guioguzhan (line 42)

gui_mainfcn(gui_State, varargin{:});

Error in

matlab.graphics.internal.figfile.FigFile/read>@(hObject,eventdata)guioguzhan('check_Callback',hObject,eventdata,guidata(hObject))

Error while evaluating UIControl Callback.

Answer 1

[Jan]

Of course a(1) and a1 are two completely different things. It is not clear, what the contents of b1 is, but maybe you want:

b1   = get(handles.input,'String') % user's input
a{1} = get(handles.q1, 'String'); % 1st character of MATLAB's string
a{2} = get(handles.q2, 'String'); % 2nd character of MATLAB's string
a{3} = get(handles.q3, 'String'); % 3rd character of MATLAB's string
a{4} = get(handles.q4, 'String'); % 4th character of MATLAB's string
a{5} = get(handles.q5, 'String'); % 5th character of MATLAB's string
correction = 0;
for i = 1:5 %% this is for obtaining correction ratio. 
    if a{i} == b1{i}
        correction = (correction + i) / 5;
    end
end

[Yusuf Oguzhan Turgut]

OK thank you. b1 is user's input. I will Use {} instead of ().

[Yusuf Oguzhan Turgut]

By the way, b1 is like /()=! . I want to get the first character of b1. Will I use this?

char(b1(1))

[Yusuf Oguzhan Turgut]

Thank you very much :) It helped me a lot :)

[Jan]

"b1 is like /()=!" is not clear enough. Prefer proper Matlab syntax instead:

b1 = '/()=!'
b1 = "/()=!"
b1 = {'/()=!'}

Maybe this is secure:

b1c = cellstring(b1);
b1_firstChar = b1c{1}(1);