ctype.h . introduction the ctype header is used for testing and converting characters. a control...
DESCRIPTION
NAME ctype.h - character types SYNOPSIS #include DESCRIPTION The header ctype.h in the ANSI C Standard Library for the C programming language contains declarations for character classification functions. Function prototypes must be provided for use with an ISO C compiler.TRANSCRIPT
CTYPE.H
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Introduction
The ctype header is used for testing and converting characters.
A control character refers to a character that is not part of the
normal printing set.
In the ASCII character set, the control characters are the
characters from 0 (NUL) through 0x1F (US), and the character
0x7F (DEL).
Printable characters are those from 0x20 (space) to 0x7E (tilde). www.ustudy.in
NAME
ctype.h - character types
SYNOPSIS
#include <ctype.h>
DESCRIPTION
• The header ctype.h in the ANSI C Standard Library for the C
programming language contains declarations for character
classification functions.
• Function prototypes must be provided for use with an ISO C
compiler. www.ustudy.in
isalnum NAME
isalnum - test for an alphanumeric character
SYNOPSIS
#include <ctype.h>
int isalnum(int c);
DESCRIPTION
• The isalnum() function tests whether c is a character of class alpha or digit in the program's
current locale, see the XBD specification, locale.
• In all cases c is an int, the value of which must be representable as an unsigned char or must
equal the value of the macro EOF. If the argument has any other value, the behavior is undefined.
RETURN VALUE
• The isalnum() function returns non-zero if c is an alphanumeric character; otherwise it returns 0.
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Example#include<ctype.h> //isalnum() #include<stdio.h> //printf() void test_isalnum() { int arr[]={'8',0xe1,'5','Z',0xfd}; int i = 0; int size = 5; for( i=0; i<size; i++) { int ret = isalnum(arr[i]); //call to the API with chars in arr[] if( (!ret) != 0 ) { printf(“ c is not alphanumeric", arr[i]); } else { printf(" %c is an alphanumeric ", arr[i]); } } } Output a is an alphanumeric5 is an alphanumericZ is an alphanumeric
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isalphaNAME
isalpha - test for an alphabetic character SYNOPSIS
#include <ctype.h> int isalpha(int c);
DESCRIPTIONThe isalpha() function tests whether c is a character of class alpha in
the program's current locale, see the XBD specification,locale. In all cases c is an int, the value of which must be representable as an
unsigned char or must equal the value of the macro EOF. If the argument has any other value, the behavior is undefined.
RETURN VALUEThe isalpha() function returns non-zero if c is an alphabetic character; otherwise it returns 0.
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Example#include<ctype.h> //isalpha() #include<stdio.h> //printf() void test_isalpha() { int arr[]={'a',0xe1,'5','Z',0xfd}; int i = 0; int size = 5; for( i=0; i<size; i++) { int ret = isalpha(arr[i]); //call to the API with chars in arr[] if( (!ret) != 0 ) { printf(“c is not an alphabet", arr[i]); } else { printf(" %c is an alphabet", arr[i]); } } } Output a is an alphabet 5 is not an alphabet Z is an alphabetwww.ustudy.in
isasciiNAME
isascii - test for a 7-bit US-ASCII character
SYNOPSIS#include <ctype.h> int isascii(int c);
DESCRIPTION• The isascii() function tests whether c is a 7-bit US-ASCII character code.
The isascii() function is defined on all integer values.
RETURN VALUE• The isascii() function returns non-zero if c is a 7-bit US-ASCII character
code between 0 and octal 0177 inclusive; otherwise it returns 0.
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iscntrl NAME
iscntrl - test for a control character
SYNOPSIS#include <ctype.h> int iscntrl(int c);
DESCRIPTIONThe iscntrl() function tests whether c is a character of class cntrl in the
program's current locale, see the XBD specification,locale. In all cases c is a type int, the value of which must be a character representable
as an unsigned char or must equal the value of the macro EOF. If the argument has any other value, the behaviour is undefined.
RETURN VALUEThe iscntrl() function returns non-zero if c is a control character; otherwise it
returns 0.
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isdigit NAME
isdigit - test for a decimal digit
SYNOPSIS#include <ctype.h> int isdigit(int c);
DESCRIPTIONThe isdigit() function tests whether c is a character of class digit in the
program's current locale, see the XBD specification, Locale . In all cases c is an int, the value of which must be a character
representable as an unsigned char or must equal the value of the macro EOF. If the argument has any other value, the behaviour is undefined.
RETURN VALUEThe isdigit() function returns non-zero if c is a decimal digit; otherwise it
returns 0. www.ustudy.in
Example#include<ctype.h> //isdigit() #include<stdio.h> //printf() void test_isdigit() { int arr[]={'8',0xe1,'5','Z',0xfd}; int i = 0; int size = 5; for( i=0; i<size; i++) { int ret = isdigit(arr[i]); //call to the API with chars in arr[] if( (!ret) != 0 ) { printf(" %c is not a digit", arr[i]); } else { printf(" %c is a digit", arr[i]); } } printf(" "); } Output 8 is a digit 5 is a digit Z is not a digit
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isxdigitNAME
isxdigit - test for a hexadecimal digit SYNOPSIS
#include <ctype.h> int isxdigit(int c);
DESCRIPTION• The isxdigit() function tests whether c is a character of class xdigit in the
program's current locale, see the XBD specification, Locale . • In all cases c is an int, the value of which must be a character representable
as an unsigned char or must equal the value of the macro EOF. If the argument has any other value, the behavior is undefined.
RETURN VALUE• The isxdigit() function returns non-zero if c is a hexadecimal digit;
otherwise it returns 0. www.ustudy.in
Example#include<ctype.h> //isxdigit() #include<stdio.h> //printf() int test_isxdigit() { int arr[]={'F','a','M','9','2'}; int i = 0; int size = 5; for( i=0; i<size; i++) { int ret = isxdigit(arr[i]); //call to the API with chars in arr[] if( (!ret) != 0 ) { printf(" %c is not hex-digit ", arr[i]); } else { printf(" %c is hex-digit", arr[i]); } } printf(" "); } Output F is hex-digit a is hex-digit M is not hex-digit 9 is hex-digit
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isgraphNAME
isgraph - test for a visible character
SYNOPSIS#include <ctype.h> int isgraph(int c);
DESCRIPTION The isgraph() function tests whether c is a character of class graph in the
program's current locale, see the XBD specification, Locale . In all cases c is an int, the value of which must be a character representable as
an unsigned char or must equal the value of the macro EOF. If the argument has any other value, the behaviour is undefined.
RETURN VALUE The isgraph() function returns non-zero if c is a character with a visible
representation; otherwise it returns 0.
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islowerNAMEislower - test for a lower-case letter
SYNOPSIS#include <ctype.h> int islower(int c);
DESCRIPTIONThe islower() function tests whether c is a character of class lower in the
program's current locale, see the XBD specification, Locale . In all cases c is an int, the value of which must be a character representable
as an unsigned char or must equal the value of the macro EOF. If the argument has any other value, the behaviour is undefined.
RETURN VALUEThe islower() function returns non-zero if c is a lower-case letter; otherwise
it returns 0. www.ustudy.in
Example#include<ctype.h> //islower() #include<stdio.h> //printf() int test_islower() { int arr[]={0x0126,0xee,'r','9','g'}; int i = 0; int size = 5; for( i=0; i<size; i++) { int ret = islower(arr[i]); //call to the API with chars in the arr[] if( (!ret) != 0 ) { printf(" %c is not in lower-case ", arr[i]); } else { printf(" %c is in lower-case", arr[i]); } } printf(" "); } Output & is not in lower-case 9 is not in lower-case g is in lower-case
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isupper NAME
isupper - test for an upper-case letter
SYNOPSIS#include <ctype.h> int isupper(int c);
DESCRIPTION The isupper() function tests whether c is a character of class upper in the
program's current locale, see the XBD specification, Locale . In all cases c is an int, the value of which must be a character representable as
an unsigned char or must equal the value of the macro EOF. If the argument has any other value, the behaviour is undefined.
RETURN VALUE The isupper() function returns non-zero if c is an upper-case letter; otherwise it
returns 0.
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Example#include<ctype.h> //isupper() #include<stdio.h> //printf() int test_isupper() { int arr[]={0x0126,'G','7','B',0x3041}; int i = 0; int size = 5; for( i=0; i<size; i++) { int ret = isupper(arr[i]); //call to the API with chars in arr[] if( (!ret) != 0 ) { printf(" %c is not in upper-case ", arr[i]); } else { printf(" %c is in upper-case", arr[i]); } } printf(" "); } Output G is in upper-case 7 is not in upper-case A is in upper-case
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isprintNAME
isprint - test for a printing character
SYNOPSIS#include <ctype.h> int isprint(int c);
DESCRIPTION The isprint() function tests whether c is a character of class print in the
program's current locale, see the XBD specification, Locale . In all cases c is an int, the value of which must be a character representable
as an unsigned char or must equal the value of the macro EOF. If the argument has any other value, the behaviour is undefined.
RETURN VALUE The isprint() function returns non-zero if c is a printing character; otherwise
it returns 0.
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ispunct NAME
ispunct - test for a punctuation character SYNOPSIS
#include <ctype.h> int ispunct(int c);
DESCRIPTIONThe ispunct() function tests whether c is a character of class punct in the
program's current locale, see the XBD specification, Locale . In all cases c is an int, the value of which must be a character
representable as an unsigned char or must equal the value of the macro EOF. If the argument has any other value, the behavior is undefined.
RETURN VALUEThe ispunct() function returns non-zero if c is a punctuation character;
otherwise it returns 0. www.ustudy.in
isspaceNAMEisspace - test for a white-space character
SYNOPSIS#include <ctype.h> int isspace(int c);
DESCRIPTIONThe isspace() function tests whether c is a character of class space in the
program's current locale, see the XBD specification, Locale . In all cases c is an int, the value of which must be a character
representable as an unsigned char or must equal the value of the macro EOF. If the argument has any other value, the behaviour is undefined.
RETURN VALUEThe isspace() function returns non-zero if c is a white-space character;
otherwise it returns 0.
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toasciiNAMEtoascii - translate integer to a 7-bit ASCII character
SYNOPSIS#include <ctype.h> int toascii(int c); DESCRIPTION• The toascii() function converts its argument into a 7-bit ASCII
character.
RETURN VALUE• The toascii() function returns the value (c & 0x7f).
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tolower NAME
tolower - transliterate upper-case characters to lower-case
SYNOPSIS
#include <ctype.h>
int tolower(int c);
DESCRIPTION
• The tolower() function has as a domain a type int, the value of which is representable as an unsigned
char or the value of EOF. If the argument has any other value, the behaviour is undefined.
• If the argument of tolower() represents an upper-case letter, and there exists a corresponding lower-
case letter (as defined by character type information in the program locale category LC_CTYPE), the
result is the corresponding lower-case letter. All other arguments in the domain are returned
unchanged.
RETURN VALUE
• On successful completion, tolower() returns the lower-case letter corresponding to the argument
passed; otherwise it returns the argument unchanged.
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Example#include <stdio.h>#include<ctype.h> int main() { printf( "Lower case of A is %c\n", tolower('A')); printf( "Lower case of 9 is %c\n", tolower('9')); printf( "Lower case of g is %c\n", tolower('g')); return 0; }
Output:Lower case of A is a Lower case of 9 is 9 Lower case of g is g
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toupperNAME
toupper - transliterate lower-case characters to upper-case
SYNOPSIS
#include <ctype.h>
int toupper(int c);
DESCRIPTION
The toupper() function has as a domain a type int, the value of which is representable as an
unsigned char or the value of EOF. If the argument has any other value, the behavior is
undefined.
If the argument of toupper() represents a lower-case letter, and there exists a corresponding
upper-case letter (as defined by character type information in the program locale category
LC_CTYPE), the result is the corresponding upper-case letter. All other arguments in the domain
are returned unchanged.
RETURN VALUE
On successful completion, toupper() returns the upper-case letter corresponding to the argument
passed. www.ustudy.in
Example#include <stdio.h>#include<ctype.h> int main() { printf( “Upper case of a is %c\n", toupper(‘a')); printf( " Upper case of 9 is %c\n", toupper('9')); printf( " Upper case of g is %c\n", toupper(‘G')); return 0; }
Output:
Upper case of a is AUpper case of 9 is 9 Upper case of G is G
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The End
Thank U
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