Synopsis
#include <ctype.h>
int isalpha(int c);
Description

isalpha returns nonzero (true) if and only if isupper or islower return true for value of the argument c.

Portability

isalpha conforms to ISO/IEC 9899:1990 (C90) and ISO/IEC 9899:1999 (C99).

See also

isupper   islower