Storing values from edit text to uitable

Hello, I have a problem with a guide, the thing that I want to do is everytime when I press the button, the value will be saved in the uitable. I did this with a for and it works, but the guide is giving me an array like it shown below, the array is always saving the last values. In the beginning of the guide, I declare z=0; that it is in global way.

       0     0
       0     0
       0     0
       0     0
      10    20
  function but1_Callback(hObject, eventdata, handles)
  global z
  a=get(handles.but1,'Value')
  if a==1;
      z=z+1;
      s1=get(handles.edit1, 'String');
      x1=str2num(s1);
      s2=get(handles.edit2, 'String');
      x2=str2num(s2);
      res=x1+x2;
      str=num2str(res);
      set(handles.edit3, 'String', str)
      data(z,:)=[x1 x2]
      set(handles.uitable1,'data',data)
  end

[Jan]

Avoid global variables. You have the handles struct, which is the perfrect location for storing a counter.

What does this mean:

 I did this with a for and it works, but the guide is giving me
 an array like it shown below

?

[Jose Alan Badillo Montes]

Sorry for the mistake, I was referring to "for loop"

Answer 1

[Geoff Hayes]

Jose - look closely at how you are updating data

 data(z,:)=[x1 x2];

As you have indicated, z is a global variable (which as Jan points out, should be avoided) and you are using it to append the new x1 and x2 to the data in the uitable. This is fine, but you haven't defined what data is at this point! :) So this line of code will create a new array of z rows with the last being [*x1* x2] and all preceding rows are zero.

You first need to get the data from the table, then update it, and then save it back. Something like the following should work

 data = get(handles.uitable1,'Data');  
 data = [data ; {x1} {x2}];
 set(handles.uitable1,'Data',data);

Try the above and see what happens! (Note that the global z should no longer be necessary.)

[Jose Alan Badillo Montes]

Thank you so much, it works, you were right I didn't need the global variable "z".