function
<cwctype>

iswalnum

int iswalnum (wint_t c);
Check if wide character is alphanumeric
Checks whether c is either an alphabetic letter (either uppercase or lowercase) or a decimal digit.

The result is true if either iswalpha or iswdigit would also return true for c.

This function is the wide-character equivalent of isalnum (<cctype>): If c translates with wctob to a character for which isalnum is true, it is always considered alphanumeric by this function too.

In C++, a locale-specific template version of this function (isalnum) exists in header <locale> for all character types.

Parameters

c
Wide character to be checked, casted to a wint_t, or WEOF.
wint_t is an integral type.

Return Value

A value different from zero (i.e., true) if indeed c is either a digit or a letter. Zero (i.e., false) otherwise.

Example

1
2
3
4
5
6
7
8
9
10
11
12
/* iswalnum example */
#include <stdio.h>
#include <wctype.h>
int main ()
{
  int i;
  wchar_t str[] = L"c3po...";
  i=0;
  while (iswalnum(str[i])) i++;
  wprintf (L"The first %d characters are alphanumeric.\n",i);
  return 0;
}

Output:
The first 4 characters are alphanumeric.


See also