The corresponding uppercase letter, if c is a lowercase ASCII character, otherwise c itself.
1 assert(toUpper('a') == 'A'); 2 assert(toUpper('A') == 'A'); 3 assert(toUpper('#') == '#'); 4 5 // N.B.: Non-ASCII Unicode lowercase letters are not converted. 6 assert(toUpper('á') == 'á');
Converts an ASCII letter to uppercase.