C type.h Library Function: The ctype.h header file of the C Standard Library declares several functions that are useful for testing and mapping characters. And all the functions accept int as a parameter, whose value must be EOF or representable as an unsigned char. While all the functions return non-zero (true) if the argument c satisfies the condition described, and zero(false) if not.
C type.h Library Function
List of inbuilt functions in ctype.h file
| Function | Description |
|---|---|
| isalpha() | checks whether the character is alphabetic |
| isdigit() | checks whether a character is a digit |
| isalnum() | Checks whether a character is alphanumeric |
| isspace() | Checks whether the character is space |
| islower() | Checks whether the character is lower case |
| isupper() | Checks whether a character is an upper case |
| isxdigit() | Checks whether the character is hexadecimal |
| iscntrl() | Checks whether a character is a control character |
| isprint() | Checks whether a character is a printable character |
| ispunct() | Checks whether the character is a punctuation |
| isgraph() | Checks whether a character is a graphical character |
| tolower() | Checks whether the character is alphabetic & converts to lower case |
| toupper() | Checks whether the character is alphabetic & converts to upper case |