C++ <cctype>

The C++ <cctype> header file declares a set of functions to classify (and transform) individual characters. For example, isupper() checks whether a character is uppercase or not.

C++ isalpha()

checks if given character is alphabet or not

C++ isblank()

checks if given character is a blank character

C++ iscntrl()

checks if given character is control character

C++ isdigit()

checks if given character is a digit or not

C++ isgraph()

checks if given character is graphic or not

C++ islower()

checks if given character is lowercase

C++ isprint()

check if given character is printable or not

C++ ispunct()

check if given character is punctuation character

C++ isspace()

check if given character is whitespace character

C++ isupper()

check if given character is uppercase or not

C++ isxdigit()

checks if given character is hexadecimal character

C++ tolower()

converts a given character to lowercase

C++ toupper()

converts a given character to uppercase