The classification function, the function library is ctype.hint isalpha (int CH) if CH is the letter ('A' - 'Z', 'A' - 'Z') returns to a non-0 value, otherwise returns 0INT IsalNum (INT CH) CH is the letter ('A' - 'Z', 'A' - 'Z') or numbers ('0' - '9') returns to a non-0 value, otherwise returns 0INT ISASCII (int CH) if ch is a character (ASCII) 0-127 in the code returns a non-0 value, otherwise returns 0INT ISCNTRL (INT CH) If the CH is a waste character (0x7f) or normal control character (0x00-0x1f) returns 0 value, return 0int isdigit (int CH) If CH is a number ('0' - '9') returns a non-0 value, if the 0int isgraph (int CH) returns a non-0 value (0x21-0x7e),
Otherwise, returning 0int islower (int CH) if the ch is lowercase letters ('A' - 'Z') returns a non-0 value, otherwise returns 0INT isprint (int CH) if the CH is a printable character (including the air) (0x20-0x7e) Return non-0 value
Otherwise, returning 0INT ISPUNCT (INTC) Returns a non-0 value if the CH is the punctuation character (0x00-0x1f), otherwise returns 0INT ISSPACE (INT CH) If CH is space (''), horizontal tab ('/ t') , Enter ('/ R'), Paper Wavel ('/ f'), vertical tab ('/ v'), the wrapper ('/ n') returns a non-0 value, otherwise returns 0Int iSupper INT CH) If the CH is uppercase letters ('a' - 'z') returns a non-0 value, otherwise returns 0INT Isxdigit (INT CH) if CH is a 16-carry number ('0' - '9', 'A'- 'F', 'A' - 'f') Returns a non-0 value, otherwise returns 0int tolower (int CH) if ch is uppercase letters ('A' - 'Z') Returns the corresponding lowercase letters ('A'-' Z ') INT Toupper (int CH) If CH is lowercase letters (' A '-' Z ') Returns the corresponding uppercase letters (' A '-' Z ')
