isupper

isspace

#include <ctype.h>int isspace(int ch);

The isspace( ) function returns nonzero if ch is a whitespace character, including space, horizontal tab, vertical tab, formfeed, carriage return, or newline characters; otherwise, zero is returned.

Related functions are isalnum( ), isalpha( ), isblank( ), iscntrl( ), isdigit( ), isgraph( ), and ispunct( ).