isalnum

---

defined in header file ctype.h

int isalnum( int c);

Checks if the given character is alphanumeric

The result is true if contains either alphabet ( lowercase or upper case) or a number, otherwise false.

Parameters

Parameter Name	Description
c	character to check, which must have value of unsigned char or EOF.

example

#include <stdio.h>
#include <ctype.h>
#include <string.h>

int main ( int argc, char* argv[])
{
	int i;
	
	char str[] = "a";
	
	if(isalnum(str[0]))
	{
		printf ("its alphanumeric character\n");
	}
	else
	{
		printf ("its NOT alphanumeric character\n");
	}
	
	return EXIT_SUCCESS;
}