HP C/iX Library Reference Manual (30026-90004)

Chapter 5 215
HP C/iX Library Function Descriptions
isalpha
isalpha
Tests whether an argument is a letter.
Syntax
#include <ctype.h>
int isalpha (int c );
Parameters
c An argument to be evaluated. The argument must be representable as an
unsigned char or the macro EOF.
Return Values
≠0 The argument passed in c is a letter.
0 The argument passed in
c is not a letter.
Description
The isalpha macro returns a nonzero value if the argument passed in c is a letter (ASCII
characters A through Z, and a through z); otherwise, the returned value is zero.
See Also
isalnum(), iscntrl(), isdigit(), isgraph(), islower(), isprint(), ispunct(),
isspace(), isupper(), isxdigit(), ANSI C 4.3.1.2, POSIX.1 8.1