The isdigit(), isalpha(), isalnum(), and isxdigit() C functions usage

 

Compiler: Visual C++ Express Edition 2005

Compiled on Platform: Windows 2003 Server Standard Edition

Header file: Standard

Additional library: none/default

Additional project setting: Set project to be compiled as C

Project -> your_project_name Properties -> Configuration Properties -> C/C++ -> Advanced -> Compiled As: Compiled as C Code (/TC)

Other info:

To do: Testing characters for their respective types

To show: The basic of isdigit(), isalpha(), isalnum(), and isxdigit() C functions usage

 

 

/* Using functions isdigit(), isalpha(), isalnum(), and isxdigit() */

#include <stdio.h>

#include <stdlib.h>

#include <ctype.h>

 

int main(void)

{

printf("Using functions isdigit(), isalpha(),\n");

printf("isalnum(), and isxdigit()\n");

printf("-------------------------------------\n");

printf("\nAccording to isdigit():\n");

isdigit('7') ? printf("7 is a digit\n") : printf("7 is not a digit\n");

isdigit('$') ? printf("$ is a digit\n") : printf("$ is not a digit\n");

printf("\nAccording to isalpha():\n");

isalpha('B') ? printf("B is a letter\n") : printf("B is not a letter\n");

isalpha('b') ? printf("b is a letter\n") : printf("b is not a letter\n");

isalpha('&') ? printf("& is a letter\n") : printf("& is not a letter\n");

isalpha('4') ? printf("4 is a letter\n") : printf("4 is not a letter\n");

printf("\nAccording to isalnum():\n");

isalnum('A') ? printf("A is a digit or a letter\n") : printf("A is not a digit or a letter\n");

isalnum('8') ? printf("8 is a digit or a letter\n") : printf("8 is not a digit or a letter\n");

isalnum('#') ? printf("# is a digit or a letter\n") : printf("# is not a digit or a letter\n");

printf("\nAccording to isxdigit():\n");

isxdigit('F') ? printf("F is a hexadecimal\n") : printf("F is not a hexadecimal\n");

isxdigit('J') ? printf("J is a hexadecimal\n") : printf("J is not a hexadecimal\n");

isxdigit('7') ? printf("7 is a hexadecimal\n") : printf("7 is not a hexadecimal\n");

isxdigit('$') ? printf("$ is a hexadecimal\n") : printf("$ is not a hexadecimal\n");

isxdigit('f') ? printf("f is a hexadecimal\n") : printf("f is not a hexadecimal\n");

 

return 0;

}

 

Output example:

 

Using functions isdigit(), isalpha(),

isalnum(), and isxdigit()

-------------------------------------

According to isdigit():

7 is a digit

$ is not a digit

According to isalpha():

B is a letter

b is a letter

& is not a letter

4 is not a letter

According to isalnum():

A is a digit or a letter

8 is a digit or a letter

# is not a digit or a letter

According to isxdigit():

F is a hexadecimal

J is not a hexadecimal

7 is a hexadecimal

$ is not a hexadecimal

f is a hexadecimal

Press any key to continue . . .

 

 

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