c 判断字符是否为字母 （iswalpha example）

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

输出

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