C ctype (ctype.h) Library
C ctype Functions
The <ctype.h>
header provides many functions for classifying and modifying characters.
Function | Description |
---|---|
isalnum() | Checks whether a character is alphanumeric |
isalpha() | Checks whether a character is a letter |
isblank() | Checks whether a character is a space or tab |
iscntrl() | Checks whether a character is a control character |
isdigit() | Checks whether a character is a decimal digit |
isgraph() | Checks whether a character has a graphical representation |
islower() | Checks whether a character is a lowercase letter |
isprint() | Checks whether a character is a printable character |
ispunct() | Checks whether a character is a punctuation character |
isspace() | Checks whether a character is a whitespace character |
isupper() | Checks whether a character is an uppercase letter |
isxdigit() | Checks whether a character is a hexadecimal digit |
tolower() | Returns a lowercase version of a character |
toupper() | Returns an uppercase version of a character |