multiple switch-case, get position value

switch var
    case {'ABC' 'ADE' 'AFG' 'AHI'}
        Str = 'A';
    case {'BAC' 'BDE' 'BFG' 'BHI'}
        Str = 'B';
end

The above is my switch-case condition. Is there a way if i select

"ADE" The Str should be "A", and the pos should 2. 
"BHI" The Str should be "B", and the pos should 4.

Is there a way i can do to get the position, or should i write switch-case again

Answer 1

[Guillaume]

switch ... case (or if ... elseif ...) statements are simple to understand and are great for beginners, but are very limited. To do what you want with a switch you'd have to split each of your case statement into 4, so you'd have

switch var
    case 'ABC'
        Str = 'A'; pos = 1;
    case 'ADE'
        Str = 'A'; pos = 2;
    ...etc

A much simpler way to do what you want is not to use switch at all, and just use look-up tables:

lookuptable = {{'ABC' 'ADE' 'AFG' 'AHI'}, 'A';
                {'BAC' 'BDE' 'BFG' 'BHI'}, 'B'};
for row = 1:size(lookuptable, 1)
   [found, pos] = ismember(var, lookuptable{row, 1});
   if found
      Str = lookuptable{row, 2};
      break;
   end
end
if found
   fprintf('"%s" found, Str is "%s" and pos is %d\n', var, Str, pos);
else
   fprintf('"%s" not found\n', var);      
end

[Walter Roberson]

[tf, idx] = ismember(Str, lookuptable(:,2));
if tf
  var = lookuptable{idx,1}{pos};
else
  var = '';
end

Answer 2

[KSSV]

str = {'ABC' 'ADE' 'AFG' 'AHI'} ;
pos = 1:length(str) ;
idx = pos(strcmp(str,'ADE'))

[Guillaume]

ismember is simplet for that:

[found, pos] = ismember('ADE', str)

Answer 3

[Walter Roberson]

Provided that you can sort the cases by initial letter and all the entries with the same initial letter are to be considered together,

   cases = {'ABC' 'ADE' 'AFG' 'AHI', 'BAC' 'BDE' 'BFG' 'BHI'};
   [vars, startpos, uidx] = unique( cellfun( @(V) V(1), cases ), 'stable');

Then,

   [tf, idx] = ismember(var, cases);
   if tf
     groupidx = uidx(idx);
     Str = vars(groupidx);
     pos = idx - startpos(groupidx) + 1;
   else
     Str = ''; pos = [];
   end