Version 1:
You can concatenate two strings like matrix elements, i.e.
str1 = 'Person A ';
str2 = 'Person B ';
str = [ str1 str2 ]
Version 2: Since you are not actually using the output, I would do:
person = [ 1 2 ];
str_all = {'Person A ', 'Person B ', 'Person C ', 'Person D ', 'Person E '};
str = [ str_all{person} ];
No need for any loop or if statements.
If the last space bothers you, just remove it at the end with
str(end) = '';
