Strings cannot be compared

After I enter in the strings into the textboxes, they will not be compared. The errors said 'Error using == Matrix dimensions must agree.' Can someone help me fix this problem. Here is my following code. Thank you.

function pushbutton1_Callback(hObject, eventdata, handles)
x = get(handles.edit1,'String');
y = get(handles.edit4,'String');

if(x == 'Rice')
    if(y == 'Noodle')
    strcmp(x, y);
    set(handles.edit2,'String','Eat rice for lunch'); 
    end
end

if(x == 'Swimming')
    if(y == 'Bowling') 
    strcmp(x, y);
    set(handles.edit2,'String','Let's go swimming'); 
    end
end

Answer 1

[Walter Roberson]

Those are not strings, those are character vectors. Strings were added in R2016b. To compare character vectors that might be of different length use strcmp()

[Guillaume]

The addition of the string class in matlab is very welcomed, but it does mean that we have to be a lot more careful about how we name char arrays. Calling a char array a string before R2016b was perfectly fine.

[Walter Roberson]

I wish they had used a different word, but I am not sure what other word they might have used.

Answer 2

[Guillaume]

You seem to sort of know that you need to use strcmp for comparing string since you've put a (useless in this case) strcmp inside your if. When comparing character vectors, you must always use strcmp

if strcmp(x, 'Rice') & strcmp(y, 'Noodle')
   set(handles.edit2,'String','Eat rice for lunch'); 
end

Or, since R2016b, you could use the new string class, where comparison is a lot more intuitive since it uses ==

if string(x) == 'Rice' & string(y) == 'Noodle'
   set(handles.edit2,'String','Eat rice for lunch'); 
end