Examples
s = 'A1,B2,C3'; isletter(s) |  |  |
check that characters of a string are alphabetic letters
res = isletter(str)
a character string.
a boolean matrix.
res = isletter(str) returns an array the same size as
str containing logical %t
(true) where the elements of str are letters of
the alphabet and logical %f (false) where they
are not.
s = 'A1,B2,C3'; isletter(s) | | |