All library function of ctype.h header file in C

In this article we will see some library function which is declared under ctype.h header file. All the library function declared inside ctype.h header file is given bellow;

  • isdigit() — isdigit() function is declared under ctype.h which checks any character that is it digit or not.
  • isalpha() — isalpha() checks whether a character is alphabet or not.
  • isspace() — isspace() function is used to check a character that is it a space or not.
  • isalnum() — isalnum() function in C is used to check whether a character is alphanumeric or not.
  • isupper() — isupper() function can check any character that is it uppercase character or not.
  • islower() — islower() can check whether a character is lowercase or not.
  • ispunct() — ispunct() function checks whether a character is a punctuation mark or not.
  • isxdigit() — This function can check whether a character is hexadecimal or not.
  • isprint() — isprint() function is defined under ctype.h header file which can check whether a character is printable or not.
  • isgraph() — isgraph() function checks a character that it is graphical character or not.
  • iscntrl() — iscntrl() character is used to check whether a character is control character or not.
  • tolower() — tolower() function is used to check that it is alphabetic or not. If alphabetic then tolower() function converts it to lowercase.
  • toupper() — toupper() function is used to check whether a character is alphabetic and then convert it to uppercase.

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