C – ctype.h library functions

 All C inbuilt functions which are declared in ctype.h header file are given below. The source code for ctype.h header file is also given below for your reference.

List of inbuilt C functions in ctype.h file:

• “ctype.h” header file support all the below functions in C language. Click on each function name below for detail description and example programs.

S.no	Function	Description
1	isalpha()	checks whether character is alphabetic
2	isdigit()	checks whether character is digit
3	isalnum()	checks whether character is alphanumeric
4	isspace()	checks whether character is space
5	islower()	checks whether character is lower case
6	isupper()	checks whether character is upper case
7	isxdigit()	checks whether character is hexadecimal
8	iscntrl()	checks whether character is a control character
9	isprint()	checks whether character is a printable character
10	ispunct()	checks whether character is a punctuation
11	isgraph()	checks whether character is a graphical character
12	tolower()	checks whether character is alphabetic & converts to lower case
13	toupper()	checks whether character is alphabetic & converts to upper case