C library - iswpunct() function

The C wctype library iswpunct() function is used to check if a given wide character (of type wint_t) is a punctuation character.

The punctuation characters are those characters that are not alphanumeric and not whitespace. It includes one of !"#$%&'()*+,-./:;?@[\]^_`{|}~ or any punctuation character specific to the current locale.

Syntax

Following is the C library syntax of iswpunct() function −

int iswpunct( wint_t ch );

Parameters

This function accepts a single parameter −

• ch − It is a wide character of type 'wint_t' to be checked.

Return Value

This function returns Non-zero value if the wide character is a punctuation character, zero otherwise.

Example 1

Following is the basic c program to demonstrate the use of iswpunct().

#include <wctype.h>
#include <wchar.h>
#include <stdio.h>

int main() {
   wchar_t wc = L'!';

   if (iswpunct(wc)) {
      wprintf(L"'%lc' is a punctuation character.\n", wc);
   } else {
      wprintf(L"'%lc' is not a punctuation character.\n", wc);
   }
   return 0;
}

Output

Following is the output −

'!' is a punctuation character.

Example 2

Let's create another c example and use the iswpunct() to identify each character in the array is whether a punctuation character or not.

#include <locale.h>
#include <stdio.h>
#include <wchar.h>
#include <wctype.h>

int main(void) {
   // "en_US.utf8" to handle Unicode characters
   setlocale(LC_ALL, "en_US.utf8");

   // Array of wide characters
   wchar_t wc[] = {L'!', L'"', L'A', L';'};
   
   size_t size = sizeof(wc) / sizeof(wc[0]);

   // Check and print if a character is punctuation character or not
   for (size_t i = 0; i < size; ++i) {
      wchar_t ch = wc[i];
      printf("Character '%lc' (%#x) is %s punctuation char\n", ch, ch, iswpunct(ch) ? "a" : "not a");
   }
   
   return 0;
}

Output

Following is the output −

Character '!' (0x21) is a punctuation char
Character '"' (0x22) is a punctuation char
Character 'A' (0x41) is not a punctuation char
Character ';' (0x3b) is a punctuation char

Example 3

This example checks the punctuation character in the default locale.

#include <locale.h>
#include <stdio.h>
#include <wchar.h>
#include <wctype.h>

int main(void) {
   // defualt locale
   setlocale(LC_ALL, "");

   // Array of wide characters
   wchar_t wc[] = {L'!', L'"', L'A', L';', L'*'};
   
   size_t size = sizeof(wc) / sizeof(wc[0]);

   // Check and print if a character is punctuation character or not
   printf("Checking punctuation characters:\n");
   for (size_t i = 0; i < size; ++i) {
      wchar_t ch = wc[i];
      printf("Character '%lc' (%#x) is %s punctuation char\n", ch, ch, iswpunct(ch) ? "a" : "not a");
   }
   
   return 0;
}

Output

Following is the output −

Checking punctuation characters:
Character '!' (0x21) is a punctuation char
Character '"' (0x22) is a punctuation char
Character 'A' (0x41) is not a punctuation char
Character ';' (0x3b) is a punctuation char
Character '*' (0x2a) is a punctuation char