Editing c/ctype.h

{{c title|<ctype.h> Header}}{{C Standard Library}}
The '''<ctype.h> header''' is part of the [[standard library]] of the [[C programming language]] that declares several functions useful for classifying and mapping characters.

Some of the functions in this header are local-specific. That is, depending on the locale chosen, some functions behave slightly differently. The minimum locale that must be provided is the "C" locale.

== Functions ==
All functions in this header take a single argument of type '''int''' which should be representable as an '''unsigned char''' or be equal to the value of the macro '''{{C|EOF}}'''. All other values result in ''undefined behavior''.

Functions in this header falls under two categories:

* [[#Character classification functions|Character classification functions]]
* [[#Character case mapping functions|Character case mapping functions]]

=== Character classification functions ===

{| class="wikitable"
|-
! Function Prototype     !! Description !! Since
|-
| {{C|ctype.h/isalnum|int isalnum(int c);}} || Checks if c is alphanumeric. || {{C|C89}}
|-
| {{C|ctype.h/isalpha|int isalpha(int c);}} || Checks if c is alphabetic. || {{C|C89}}
|-
| {{C|ctype.h/isblank|int isblank(int c);}} || Checks if c is blank. || [[C99]]
|-
| {{C|ctype.h/iscntrl|int iscntrl(int c);}} || Checks if c is a control character. || {{C|C89}}
|-
| {{C|ctype.h/isdigit|int isdigit(int c);}} || Checks if c is a decimal digit. || {{C|C89}}
|-
| {{C|ctype.h/isgraph|int isgraph(int c);}} || Checks if c has a graphical representation. || {{C|C89}}
|-
| {{C|ctype.h/islower|int islower(int c);}} || Checks if c is a lowercase letter. || {{C|C89}}
|-
| {{C|ctype.h/isprint|int isprint(int c);}} || Checks if c is printable. || {{C|C89}}
|-
| {{C|ctype.h/ispunct|int ispunct(int c);}} || Checks if c is a punctuation character. || {{C|C89}}
|-
| {{C|ctype.h/isspace|int isspace(int c);}} || Checks if c is a white-space character. || {{C|C89}}
|-
| {{C|ctype.h/isupper|int isupper(int c);}} || Checks if c is an uppercase letter. || {{C|C89}}
|-
| {{C|ctype.h/isxdigit|int isxdigit(int c);}} || Checks if c is a hexadecimal digit. || {{C|C89}}
|}

=== Character case mapping functions ===
Two functions that deal with character case mapping is provided.

{| class="wikitable"
|-
! Function Prototype	 !! Description !! Since
|-
| {{C|ctype.h/tolower|int tolower(int c);}} || Converts an uppercase letter to a corresponding lowercase letter. || {{C|C89}}
|-
| {{C|ctype.h/toupper|int toupper(int c);}} || Converts a lowercase letter to a corresponding uppercase letter. || {{C|C89}}
|-
|}


{{DEFAULTSORT:Ctype.h - C}}
[[Category:C standard library]]
[[Category:Ctype.h - C]]