Insert an element once in a listbox

I wrote the following code that allows me to insert the word "Cab1" in a list once the condition is true

if (Output == 1) 

        str = get(handles.list_Update, 'string'); 
        str = cellstr(str); 
        str{end+1} = 'Cab1'; 
        set(handles.list_Update, 'String', str); 
  end

But I get the result below because the condition "Output = 1" is still true. I want to insert the word "Cab1" only once in the list even if Output remains at 1. Can a Brake help me to solve the problem otherwise how to do it?

Answer 1

[KL]

Check if your string already existing in your listbox and make output false in that case?

Something like,

if (Output == 1) 
        str = get(handles.list_Update, 'string'); 
        str = cellstr(str);
        if find(ismember(str, 'cab1'))
           output = 0;
        else 
           str{end+1} = 'Cab1'; 
           set(handles.list_Update, 'String', str);
       end 
end

[Samah EL QASSAH]

Thanks KL for the help, yes, but I don't want to set the "Output" to 0

[KL]

If you don't want to set the output to be zero, you can do nothing under the true case and simply return to your main routine.