Same codes do not work ?

I want to ask that these two codes are same ? if it is they do not work as same job, if it is not, what is the mean both of them ? and where I can use them in which situations ?

theta=str2double(get(handles.hObject,'String'));

handles.theta=str2double(get(hObject,'String'));

Answer 1

[Image Analyst]

It looks like you're using GUIDE. The first one takes the target of the callback, presumably an edit field or something, and assigns it to a local variable that lives just within that callback and vanishes when you're done executing that callback.

The second one attaches (or replaces if it already exists) theta as a member to the handles structure, which, if you call guidata() before you exit the callback, will survive and be seen in other callbacks.

[engineerOfPhysics]

Your explanation is so helpful thanks for that ..

Can you give an example to use them where can be ?