C Library - <ctype.h>

The ctype.h header file of the C Standard Library declares several functions that are useful for testing and mapping characters.

Library Functions

This function checks whether the passed character is alphanumeric.

This function checks whether the passed character is alphabetic.

This function checks whether the passed character is control character.

This function checks whether the passed character is decimal digit.

This function checks whether the passed character has graphical representation using locale.

This function checks whether the passed character is lowercase letter.

This function checks whether the passed character is printable.

This function checks whether the passed character is a punctuation character.

This function checks whether the passed character is white-space.

This function checks whether the passed character is an uppercase letter.

This function checks whether the passed character is a hexadecimal digit.

This function converts uppercase letters to lowercase.

This function converts lowercase letters to uppercase.