what does ismember actually mean?

S={'NH4Cl'; 'MgCl2'; 'CaCl2'; 'ZnCl2'; 'ZnSO4'; 'NaCl'};
str={'Choose the combinations of salts available'};
result=listdlg('Promptstring',str, 'ListSize', [100,100], 'ListString', S, ...
                                     'SelectionMode', 'multiple');
if all(ismember(result,[1 3]))
  disp('hei')
end 

in this code (all (ismember...), does the chronology of user's choice has to say anything or does ismember mean that user could have chosen the item 1 first and then 3 or 3 first and then 1? asking because then I have to take this into account in the if statement

[dpb]

The logical vector returned by ismember is relative to the members in the first argument in the call -- in your case the array result. However, as you've written it with all, the condition will only be true if the user selects both 1 and 3 from the dialog box -- probably not what you're after.

Answer 1

[Star Strider]

If I understand your Question correctly, the logical vector created by ismember will be in the order the elements appear in ‘result’. However that is likely irrelevant because you are calling the all function. So either they both match (the all condition will be true) or one or none match (the all condition will be false).