### <ctype.h>

The <ctype.h> include file defines functions used in character classification. The functions defined in <ctype.h> are:

isalnum | iscntrl | isprint | islower | tolower
isalpha | isdigit | ispunct | isupper | toupper
isblank | isgraph | isspace | isxdigit |

In extended mode, <ctype.h> also includes definitions for the following IBM C and C++ Compilers extensions:

isascii | _iscsymf | _toascii | _tolower | _toupper
_iscsym |  |  |  |

For both OS/2 and Windows, in IBM C and C++ Compilers, the <ctype.h> functions are all implemented as macros.

#include