ctype.h

Methods

Return	Method
int	isalnum( int c )
int	isalpha( int c )
int	isdigit( int c )
int	ispunct( int c )
int	isspace( int c )
int	isupper( int c )
int	islower( int c )
int	toupper( int c )
int	tolower( int c )

Method Descriptions

int isalnum( int c )

Checks whether c is alphabetic or numeric, A-Z, a-z or 0-9.

Returns 1 if so, returns 0 otherwise.

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int isalpha( int c )

Checks whether c is alphabetic, A-Z or a-z.

Returns 1 if so, returns 0 otherwise.

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int isdigit( int c )

Checks whether c is a decimal digit, 0-9.

Returns 1 if so, returns 0 otherwise.

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int ispunct( int c )

Checks whether c is a punctuation character found below.

! " # $ % & ' ( ) * + , - . / : ; < = > ? @ [ \ ] ^ _ ` { | } ~

Returns 1 if so, returns 0 otherwise.

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int isspace( int c )

Checks whether c is a white-space character found below.

\t \n \v \f \r

Returns 1 if so, returns 0 otherwise.

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int isupper( int c )

Checks whether c is an uppercase letter, A-Z.

Returns 1 if so, returns 0 otherwise.

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int islower( int c )

Checks whether c is a lowercase letter, a-z.

Returns 1 if so, returns 0 otherwise.

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int toupper( int c )

Returns an uppercase equivalent of c.

Returns c if not alphabetic.

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int tolower( int c )

Returns a lowercase equivalent of c.

Returns c if not alphabetic.

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