c 判断一个字符是否为字母

#include <stdio.h>
#include <wctype.h>
int main ()
{
  int i=;
  wchar_t str[] = L"C++";
  while (str[i])
  {
    if (iswalpha(str[i])) wprintf (L"character %lc is alphabetic\n",str[i]);
    else wprintf (L"character %lc is not alphabetic\n",str[i]);
    i++;
  }
  return ;
}

输出

character C is alphabetic
character + is not alphabetic
character + is not alphabetic