#include <ctype.h>
int ft_isalpha(int c);
DESCRIPTION:
Checks for an alphabetic character
In the standard “C” locale, it is equivalent to (ft_isupper() || ft_islower()). In some locales, there may be additional characters for which ft_isalpha() is true — letters which are neither uppercase nor lowercase.
RETURN VALUE:
The values returned are nonzero if the character c falls into the tested class, and zero if not.
classification character libft