Note that your mykey is a string array. We typically use the term matrix only when referring to numeric arrays.
Also note that "1234" is not a number. It's the textual representation of a number. It would indeed be better if you stored the numbers as actual numbers rather than text, eg:
mymap = containers.Map([1234, 5678], ["A", "B"]);
or
mytable = table([1234; 5678], ["A"; "B"], 'VariableNames', {'key', 'value'});
Either of these make it trivial to retrieve the value associated with a key:
%using containers.Map
searchkey = input('Enter a single number');
if isKey(mymap, searchkey)
fprintf('The value matching key %d is: %s\n\n', searchkey, mymap(searchkey)); %mymap(searchkey) returns the corresponding value
end
searchkeys = input('Enter an array of number')
[found, whichindex] = ismember(searchkeys, mymap.Keys);
keysfound = searchkeys(found);
matchingvalues = mymap.Values(whichindex(found));
fprintf('These numbers were found: [%s]\n', strjoin(compose('%d', keysfound), ', '));
fprintf('Matching values are: [%s]\n\n', strjoin(matchingvalues, ', '));
%using a table
searchkeys = input('Enter one or more number');
[~, where] = ismember(searchkeys, mytable.key);
keysfound = mytable.key(where);
matchingvalues = mytable.values(where);
fprintf('These numbers were found: [%s]\n', strjoin(compose('%d', keysfound), ','));
fprintf('Matching values are: [%s\n\n', strjoin(matchingvalues, ','));
Note that all of the above works even if the keys are actually strings but storing numbers as numbers is more efficient (faster comparison, less memory used).
