C – iscntrl() function

Prev     Next

  • iscntrl( ) function in C language checks whether given character is control character or not. Syntax for iscntrl( ) function is given below.

int iscntrl( int x );

  • Control characters in C language are ‘\a’ ( alert ), ‘\b’ ( backspace ), ‘\f’ ( form feed ), ‘\n’ ( new line ), ‘\r’ ( carriage return ), ‘\t’ ( horizondal tab),  ‘\v’ ( vertical tab) and ‘\0’ ( null ).


  • ‘\a’ – Alert character is used to produce visible or audible alert in output.
  • ‘\b’ -It is used to move the position of pointer to one position back in current line.
  • ‘\f’ – form feed character is used to start a new page.
  • ‘\n’- new line character moves to the next line from the current line.
  • ‘\r’ – carriage return is used to move the position to the beginning of current line.
  • ‘\t’ – It is used to move the pointer to the horizontal tab space in current line.

Example program for iscntrl() function in C:


control character is found at 4th position

Other Int, Char validation functions in C programming language:

  • All “int, char validation functions” used in C programming language are given below. “ctype.h” header file support all these functions in C language.
  • Click on each function name below for detail description and example programs.
Functions Description
isalpha() checks whether character is alphabetic
isdigit() checks whether character is digit
isalnum() Checks whether character is alphanumeric
isspace() Checks whether character is space
islower() Checks whether character is lower case
isupper() Checks whether character is upper case
isxdigit() Checks whether character is hexadecimal
iscntrl() Checks whether character is a control character
isprint() Checks whether character is a printable character
ispunct() Checks whether character is a punctuation
isgraph() Checks whether character is a graphical character
tolower() Checks whether character is alphabetic & converts to lower case
toupper() Checks whether character is alphabetic & converts to upper case

Prev     Next

Ask your questions or clarify your/others doubts from,

✅ Online Discussion Forums by Fresh2Refresh.com

Share this website !!!
Facebook Twitter Linkedin

We Support JALLIKATTU !!!
By Fresh2Refresh.com
Show Your Support as well. Thanks!